Azoindoxylverfahren zum Hydrolasennachweis

Zusammenfassung Untersucht wird die Eignung verschiedener Azoindoxyl-methoden zum lichtmikroskopisch-histochemischen Nachweis der -N-Acetylglucosaminidase. Die Inkubationsmedien enthalten 0,5 mg N-Acetyl-(5-bromindol-3-yl)--d-glucosaminid (5-Br-3-Indolyl--d-N-acetylglucosaminid; 1 mg gelöst in 0,05 ml Dimethylformamid) in 1 ml 0,1 M Citronensäure-Phosphat-Puffer, pH 4,5 oder 5. Als Simultankuppler werden 0,02 ml Hexazonium-p-rosanilin oder-neufuchsin oder tetrazotiertes BAXD/ml oder 0,5 mg Fast Blue B oder Fast Garnet GBC/ml erprobt. Die besten Resultate liefert unabhängig von Gewebevorbehandlung und Organ hexazotiertes Neufuchsin.Im Vergleich zur Azofarbstoffreaktion mit Naphthol-AS-BI--d-N-acetylglucosaminid und hexazotiertem p-Rosanilin oder Neufuchsin oder tetrazotiertem BAXD liefert speziell die Azoindoxylmethode mit hexazotiertem Neufuchsin bessere oder identische Resultate. Die Indigogen-, Metallsalzund Tetrazoliumreaktion sind dem Azoindoxylverfahren meistens unterlegen; eine Ausnahme macht die Tetrazoliummethode mit BSPT.Beim Azoindoxylverfahren mit Hexazonium-p-rosanilin ist vorteilhaft, daß der Azoindoxylfarbstoff osmiert werden kann, in organischen Solventien und Kunstharzen weitgehend unlöslich ist und deshalb für die ultracytochemische Darstellung der -N-Acetylglucosaminidase in Frage kommt. Unter den übrigen Methoden ist dies nur noch mit der Tetrazoliumreaktion und BSPT der Fall; sein Formazan läßt sich ebenfalls osmieren.Mit hexazotiertem Neufuchsin zur Simultankupplung und 5-Br-3-Indolyl--d-glucosaminid als Substrat kann die -N-Acetylglucosaminidase nach Blockfixation in Form- oder Glutaraldehyd in den Lysosomen zahlreicher Rattenorgane und-gewebe einwandfrei nachgewiesen werden.

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Azoindoxyl methods for the investigation of hydrolasesIII. Histochemical studies of -d-N-acetylglucosaminidase

Summary The suitability of various azoindoxyl procedures for the light microscopical demonstration of -N-acetylglucosaminidase is described. The incubation media tried consist of 0.5 mg N-Acetyl-(5-bromindol-3-yl)--d-glucosaminide (5-Br-3-indolyl--d-N-acetylglucosaminide; 1 mg dissolved in 0.05 ml N,N-dimethylformamide) in 1 ml 0.1 M citric acid phosphate buffer, pH 4.5 or 5. 0.02 ml hexazotized p-rosaniline or new fuchsine/ml or tetrazotized BAXD or 0.5 mg Fast Blue B or Garnet GBC/ml were employed as a coupling reagent. Hexazotized new fuchsine yields the best results independent on the pretreatment of the tissue and the organ investigated followed by hexazonium-p-rosaniline.Compared with the azo dye method using naphthol AS-BI -d-N-acetyl-glucosaminide as a substrate and hexazotized p-rosaniline or new fuchsine or tetrazotized BAXD for simultaneous coupling especially the azoindoxyl technique with the new fuchsine is equivalent or superior. When the indolyl glucosaminide is used in the indigogenic, tetrazolium or metal precipitation method the results are mostly inferior with the exception of the tetrazolium reaction using BSPT.However, the main advantage of the azoindoxyl procedure is that at least the azoindoxyl dye deriving from hexazotized p-rosaniline can be osmificated and withstands treatment with organic solvents and resins. Therefore, the reaction product seems to be suitable for the electron microscopic demonstration of glucosaminidase. Among the other reaction principles this can reliably be achieved only with BSPT as a tetrazolium salt followed by osmification of its formazan.After fixation of blocks of tissue in form- or glutaraldehyde -d-N-acetylglucosaminidase can be localized with 5-Br-3-indoxyl--d-N-acetylglucosaminide as a substrate and hexazotized new fuchsine for simultaneous coupling in the lysosomes of many rat organs.

     

Azoindoxyl methods for the investigation of hydrolases. IV. Suitability of various diazonium salts (author's transl)]

Using fresh frozen, freeze-dried or cryostate sections from aldehyde fixed rat tissues 13 diazonium salts were tested as simultaneous coupling reagents for the localization of acid, neutral and alkaline hydrolases with azo indoxyl methods. Hexazotized new fuchsine and/or Fast blue B are the diazonium salts of choice for the demonstration of acid beta-galactosidase, neuraminidase, beta-N-acetylglucosaminidase, acid phosphatase, and non-specific esterase followed by hexazotized p-rosaniline. Fast blue VB, BB and RR and Fast violet B are recommended for the investigation of alkaline phosphatase and lactase, Fast garnet GBC for acid beta-galactosidase, glucosaminidase and lactase. Fast red B, RC, RL and TR and Fast black K can only be employed for lactase studies. The exact concentration of the coupling reagent depends on the activity of the enzyme and the organ imvestigated. On the average 0.01-0.02 ml unstable diazonium salt/ml and 0.3--1 microgram stable diazonium salt/ml are sufficient for the correct localization of these hydrolases. Freeze-dried cryostat sections yield the best results in the demonstration of lactase and alkaline phosphatase independent on the coupling reagent used. Sections from formaldehyde or glutaraldehyde fixed organs are superior for the localization of the other hydrolases; an exception is the investigation of acid beta-galactosidase and glucosaminidase with Fast garnet GBC. Then, excellent results are obtained also with freeze-dried material. Fresh frozen sections are suitable for the localization of lactase with hexazotized new fuchsine or p-rosaniline and of alkaline phosphatase with Fast blue VB and BB or violet B. The total activity of acid, neutral and alkaline hydrolases can be investigated using semipermeable membranes in combination with all unstable and stable diazonium salts of choice. Reliable osmification of the azoindoxyl dye is only possible if hexazotized p-rosaniline is employed for coupling; without further posttreatment all azoindoxyl dyes are extracted by ethanol, isopropanol or xylol. 7 incubation media are given for the demonstration of hydrolases with azoindoxyl methods at the level of light microscopy for routine studies and typical examples for the application of these methods are presented. A modified procedure is described for the freeze-drying of cryostat sections with the Edwards-Pearse tissue dryer EPD3.     

Histochemical detection of alpha-D-glucosidases and their molecular forms with 5-Br-4-Cl-3-indoxyl-alpha-D-glucoside

5-Br-4-Cl-3-Indoxyl-alpha-D-gluco(pyrano)side was found to be the most suitable synthetic substrate for the demonstration of alpha-D-glucosidases in situ. Using an azoindoxyl procedure with hexazotized pararosaniline or new fuchsine at pH 5 in freeze-dried celloidine-mounted cryostat sections acid alpha-D-glucosidase (EC 3.2.1.20) was shown for the first time in lysosomes of many cells of fetal and adult rat, mouse, guinea-pig, marmoset and human organs. At pH 6.5, in chloroform-acetone pretreated cryostat sections plasma membrane alpha-D-glucosidases were shown in the brush border of enterocytes of the small and large intestine, in the brush border of proximal renal tubule cells and in the stereocilia of the epididymal duct. In an indigogenic procedure with ferricyanide/ferrocyanide as redox catalysator plasma membrane alpha-D-glucosidases were depicted as well as with the azo-indoxyl method; the demonstration of the acid alpha-D-glucosidase was inferior to that achieved with the azo-indoxyl procedure. Using tetrazolium salts as capture reagent intracellular localization was unsatisfactory. In enterocytes, a localization in the Golgi apparatus was shown by the azo-indoxyl procedure only. Analytical isoelectric focusing revealed organ-dependent differences of plasma membrane and lysosomal alpha-D-glucosidases. Compared with the already existing methods the azo-indoxyl and indigogenic procedures are by far the most suitable techniques.     

Peptidases II. Localization of dipeptidylpeptidase IV (DPP IV). Histochemical and biochemical study]

Fresh frozen, unfixed, chloroforme-acetone treated or freeze-dried cryostat sections or sections from aldehyde-fixed blocks of tissue were tried for the histochemical investigation of dipeptidylpeptidase IV (DPP IV) with L-glycyl-L-prolyl(gly-pro)-naphthylamides as substrates and stable or unstable diazonium salts for simultaneous coupling and various buffers, pH 5--7.5 in rats, mice, guinea-pigs, cats, rabbits, hamsters and human enterobiopsies. The best results are obtained with 1.7--3.4 mM gly-pro-4-methoxy-2-naphthylamide and 1 mg Fast Blue B/ml or (with some limitations) 0.025 ml hexazotized new fuchsine/ml in 0.1 M cacodylate or phosphate buffer, pH 7.5 and unfixed sections for the demonstration of the total activity of DPP IV and freeze-dried celloidin-mounted cryostat sections for the precise localization of the enzyme or the detection of lysosomes, Golgi apparatus and secretion granules sections from aldehyde fixed tissue blocks are only suitable to study the lysosomal hydrolysis of gly-pro-naphthylamides between pH 5 and 7 when hexazotized p-rosaniline or new fuchsine are employed. DPP IV is firmly bound to strutures and shows species- and organ-dependent differences. In general, the enzyme occurs in the capillary endothelium, sinusoidal cells, perineurium, epithelial cells of intercalated and striated ducts, microvillous zone of intestinal crypts and villi, uterus, Fallopian tubes, ductus epididymis and proximal renal tubules, hepatocyte and lymphocyte membrane, plasmalemma of pseudostratified and transient epithelia and in the capsules and interstitium of many organs. These sites of activity can be completely inhibited by diisopropyl fluorophosphate and partially by Pb2+; Mg2+, Mn2+, Co2+ EDTA are without any influence. Phenantrolin may activate DPP IV. The biochemical assay works with 10 mM gly-pro-2-naphthylamide in 0.1 M cacodylate buffer, pH 7; the enzyme activity is determined fluorometrically in guinea-pig and rat organs; the data confirm and enlarge the species- and organ-dependent differences revealed by histochemistry. Compared with other dipeptide as well as tripeptide and amino acid naphthylamides the results obtained for DPP IV suggest a peptidylpeptidase which seems to be involved in other metabolic processes beside the degradation of collagen.     

Azoindoxyl methods for the histochemical investigation of hydrolases. I. Lactase (lactase-beta-glucosidase complex) (author's transl)]

An azoindozyl method for the histochemical demonstration of lactase (lactase-beta-glucosidase complex) is described. The incubation medium consists of 5 mg 5-Br-4-Cl-3-indolyl-beta-D-fucoside (dissolved in 0.5 ml N,N-dimethylformamide) and 0.02 ml hexazotized prosaniline in 10 ml 0.1 M citric acid phosphate buffer, pH 6-6.5. By means of this method lactase can be exactly localized in the brush border of the enterozytes in the jejunum of suckling rats. Compared to the corresponding indigogenic method the azoindoxyl reaction proceeds faster and the reaction product is often precipitated more precisely.     

Azoindoxylverfahren zum histochemischen Hydrolasennachweis

Zusammenfassung Es wird eine Azoindoxylmethode zum histochemischen Nachweis der Lactase (Lactase--glucosidase-Komplex) beschrieben.Das Inkubationsmedium enthält 5 mg 5-Br-4-Cl-3-Indolyl--d-fucoside (gelöst in 0,5 ml N,N-Dimethylformamid) und 0,02 ml Hexazonium-p-rosanilin in 10 ml 0,1 M Citronensäure-Phosphat-Puffer, pH 6–6,5.Mit diesem Verfahren kann die Lactase im Jejunum von Rattensäuglingen exakt im Bürstensaum der Enterozyten dargestellt werden. Verglichen mit der entsprechenden Indigogenmethode läuft die Azoindoxylreaktion schneller ab und lokalisiert in frischem und fixiertem Material häufig präziser.

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Azoindoxyl methods for the histochemical investigation of hydrolases. I. Lactase (lactase--glucosidase complex)

Summary An azoindoxyl method for the histochemical demonstration of lactase (lactase--glucosidase complex) is described.The incubation medium consists of 5 mg 5-Br-4-Cl-3-indolyl--d-fucoside (dissolved in 0.5 ml N,N-dimethylformamide) and 0.02 ml hexazotized p-rosaniline in 10 ml 0.1 M citric acid phosphate buffer, pH 6–6.5.By means of this method lactase can be exactly localized in the brush border of the enterozytes in the jejunum of suckling rats. Compared to the corresponding indigogenic method the azoindoxyl reaction proceeds faster and the reaction product is often precipitated more precisely.

     

Azoindoxylverfahren zum Hydrolasennachweis

Zusammenfassung An frischen, gefriergetrockneten und Schnitten von aldehyd-fixierten Rattengeweben werden 13 Diazoniumsalze als Simultankuppler zum Nachweis saurer, neutraler und alkalischer Hydrolasen mit Azoindoxylverfahren geprüft. Hexazotiertes Neufuchsin und/oder Fast Blue B sind die Diazoniumsalze der Wahl zur Lokalisation von saurer -Galactosidase, Neuraminidase, -N-Acetylglucosaminidase, saurer Phosphatase und unspezifischer Esterase gefolgt von Hexazonium-p-rosanilin. Fast Blue VB, BB und RR sowie Fast Violet B eignen sich zur Untersuchung von Lactase und alkalischer Phosphatase; Fast Garnet GBC kann zur Lokalisation von saurer -Galactosidase, Glucosaminidase und Lactase, Fast Red B, RC, RL und TR sowie Black K nur für Lactase-Studien verwandt werden. Durchschnittlich reichen 0,01–0,02 ml instabiles Diazoniumsalz und 0,3–1 mg stabiles Diazoniumsalz/ml zur korrekten Lokalisation dieser Hydrolasen aus. Im einzelnen hängt die Kupplerkonzentration von der Enzymaktivität und vom untersuchten Organ ab. Gefriergetrocknete Kryostatschnitte liefern unabhängig vom Kuppler die besten Resultate bei Untersuchung von Lactase und alkalischer Phosphatase; Schnitte von form- oder glutaraldehyd-fixierten Organen sind beim Nachweis der restlichen Hydrolasen überlegen. Eine Ausnahme macht die Untersuchung der sauren -Galactosidase und Glucosaminidase mit Fast Garnet GBC; dann werden die besten Ergebnisse nach Gefriertrocknung erzielt.Frische Kryostatschnitte sind zur Darstellung der Lactase mit hexazotiertem Neufuchsin oder p-Rosanilin und der alkalischen Phosphatase mit Fast Blue VB und BB sowie Violet B geeignet; die Gesamtaktivität der sauren, neutralen und alkalischen Hydrolasen kann mit semipermeablen Membranen und den stabilen sowie instabilen Diazoniumsalzen der Wahl untersucht werden.Ausreichende Osmierung der Azoindoxylfarbstoffe ist nur möglich, wenn Hexazonium-p-rosanilin als Kupplungsreagens benutzt wird; ohne Vorbehandlung extrahieren Äthanol, Isopropanol und Xylol alle Azoindoxyle.7 Inkubationsmedien werden zum lichtmikroskopisch-histochemischen Nachweis von Glykosidasen, Esterasen und Phosphatasen mit Azoindoxylmethoden angegeben und typische Anwendungsbeispiele genannt. Zur Gefriertrocknung von Kryostatschnitten mit dem Edwards-Pearse Gewebetrockner EPD 3 wird ein modifiziertes Verfahren beschrieben.

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Azoindoxyl methods for the investigation of hydrolasesIV. Suitability of various diazonium salts

Summary Using fresh frozen, freeze-dried or cryostate sections from aldehyde fixed rat tissues 13 diazonium salts were tested as simultaneous coupling reagents for the localization of acid, neutral and alkaline hydrolases with azo indoxyl methods. Hexazotized new fuchsine and/or Fast blue B are the diazonium salts of choice for the demonstration of acid -galactosidase, neuraminidase, -N-acetylglucosaminidase, acid phosphatase, and non-specific esterase followed by hexazotized p-rosaniline. Fast blue VB, BB and RR and Fast violet B are recommended for the investigation of alkaline phosphatase and lactase, Fast garnet GBC for acid -galactosidase, glucosaminidase and lactase. Fast red B, RC, RL and TR and Fast black K can only be employed for lactase studies. The exact concentration of the coupling reagent depends on the activity of the enzyme and the organ investigated. On the average 0.01–0.02 ml unstable diazonium salt/ml and 0.3–1 mg stable diazonium salt/ml are sufficient for the correct localization of these hydrolases. Freeze-dried cryostat sections yield the best results in the demonstration of lactase and alkaline phosphatase independent on the coupling reagent used. Sections from formaldehyde or glutaraldehyde fixed organs are superior for the localization of the other hydrolases; an exception is the investigation of acid -galactosidase and glucosaminidase with Fast garnet GBC. Then, excellent results are obtained also with freeze-dried material.Fresh frozen sections are suitable for the localization of lactase with hexazotized new fuchsine or p-rosaniline and of alkaline phosphatase with Fast blue VB and BB or violet B. The total activity of acid, neutral and alkaline hydrolases can be investigated using semipermeable membranes in combination with all unstable and stable diazonium salts of choice.Reliable osmification of the azoindoxyl dye is only possible if hexazotized p-rosaniline is employed for coupling; without further posttreatment all azoindoxyl dyes are extracted by ethanol, isopropanol or xylol.7 incubation media are given for the demonstration of hydrolases with azoindoxyl methods at the level of light microscopy for routine studies and typical examples for the application of these methods are presented. A modified procedure is described for the freeze-drying of cryostat sections with the Edwards-Pearse tissue dryer EPD 3.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft (SFB 105)     

Azoindoxylverfahren zum Hydrolasennachweis

Zusammenfassung Nach Ermittlung verschiedener Reaktionskonstanten resultiert folgender Ansatz zur photometrischen Bestimmung der sauren-Galactosidase (Messung des Azoindoxylfarbstoffs bei 540 nm nach Extraktion mit Dimethylformamid oder-acetamid): 1,5 mM 5-Br-4-Cl-3-Indolyl--d-galactosid (1 mg gelöst in 0,05 ml Dimethylformamid) und 0,01–0,015 ml Hexazonium-p-rosanilin/ml in 0,1 M Citronensäure-Phosphat-Puffer, pH 4. Die damit untersuchten Rattenorgane besitzen unterschiedliche Aktivitäten an saurer-Galactosidase; NaCl läßt die Enzymaktivität unbeeinflußt. — ähnliche Resultate liefert das Indigogen-Verfahren; Indigo kann wie der Azoindoxylfarbstoff gelöst und gemessen werden.Hexazotiertes p-Rosanilin in höheren Konzentrationen hemmt die saure-Galactosidase zu etwa 50%; niedrige sowie Ferricyanid-Ferrocyanid inhibieren nicht. Die Hemmwirkung von Glutar- und Formaldehyd läßt sich mit dem Azoindoxylverfahren nicht messen, da der Farbstoff unvollständig aus fixiertem Material extrahiert wird.Auf Grund der biochemischen Befunde ergibt sich nachstehendes histochemisches Medium zur Darstellung der sauren-Galactosidase: 7,5 (1,5 mM) 5-Br-4-Cl-3-Indolyl--d-galactosid (gelöst in 0,25 ml Dimethylformamid) und 0,05–0,15 ml Hexazonium-p-rosanilin in 10 ml 0,1 M Citronensäure-Phosphat-Puffer, pH 4. Nach der Inkubation können die Schnitte osmiert, dehydriert und in Kunstharz oder ohne Osmierung in Glycerin-Gelatine eingedeckt werden. Das Osmiumchelat ist in organischen Solventien unlöslich; seine Stabilität hängt von der Hexazonium-p-rosanilin-Konzentration ab.Mit dieser Methode läßt sich die saure-Galactosidase nach Fixation in Glutaraldehyd oder einem Glutaraldehyd-Formaldehyd-Gemisch exakt in den Lysosomen zahlreicher Rattenorgane erfassen.Verglichen mit dem Indigogen- und Metallsalzverfahren und den simultanen Azokupplungsreaktionen zum histochemischen Nachweis der sauren-Galactosidase ist die Azoindoxyltechnik überlegen oder gleichwertig; der biochemische Ansatz leistet Nützliches für kombinierte quantitativ-qualitative Studien des Enzyms.

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Azoindoxyl methods for the investigation of hydrolases

Summary The determination of various reaction constants yields the following assay for the photometric evaluation of acid-galactosidase (measurement of the azoindoxyl dye at 540 nm after extraction with dimethylformamide or-acetamide): 1.5 mM 5-Br-4-Cl-3-indolyl--d-galactoside (1 mg dissolved in 0.05 ml dimethylformamide) and 0.01–0.015 ml hexazotized p-rosaniline/ml in 0.1 M citric acid-phosphate buffer, pH 4. By means of this procedure it becomes evident that the activity of the enzyme differs considerably in various rat organs; NaCl does not influence acid-galactosidase. — Similar results were obtained with the indigogenic method; indigo can be dissolved and measured photometrically as the azoindoxyl dye.The enzyme is suppressed by high concentrations of hexazotized p-rosaniline to 50%; low concentrations do not inhibit; the same is true for ferricyanide-ferrocyanide employed in the indigogenic media. — The effect of glutar-and formaldehyde on acid-galactosidase cannot be investigated with the azoindoxyl reaction since the azoindoxyl dye partially withstands extraction from fixed blocks of tissue.On the basis of the biochemical findings the azoindoxyl technique can be recommended for the histochemical demonstration of acid-galactosidase: 7.5 mg (1.5 mM) 5-Br-4-Cl-3-indolyl--d-galactoside (dissolved in 0.25 ml dimethylformamide) and 0.05–0.15 ml hexazonium-p-rosaniline in 10 ml 0.1 M citric acid-phosphate buffer, pH 4. After incubation the sections can be treated with osmium tetroxide followed by dehydration and mounting in resins or can be mounted without prior osmification of the azoindoxyl dye in glycerin jelly. The osmium chelate resists treatment with organic solvents; the stability of the chelate depends on the concentration of hexazotized p-rosaniline.After fixation in glutaraldehyde or in a mixture of form- and glutaraldehyde acid-galactosidase can be exactly localized in the lysosomes of many rat organs.In comparison with the indigogenic, the metal precipitation and the simultaneous azocoupling reactions for the in situ detection of acid-galactosidase the azoindoxyl procedure is superior if fixed material is used; it is equivalent or inferior in connection with the membrane technique. The biochemical azoindoxyl assay represents a useful method for combined qualitative and quantitative studies of acid-galactosidase.

     

Peptidases. I. Histochemical investigations with 2-naphthylamides and hexazonium-p-rosanilin (author's transl)]

Using fresh frozen (with and without semipermeable membranes), freeze-dried or sections from aldehyde fixed material and hexazotized p-rosaniline for simultaneous coupling more than 20 different unsubstituted or substituted L-amino acid naphthylamides are split especially in the microvilli and/or stereocilia of the small intestine, kidney and epididymis from rats. Further sites of positive reactions can be revealed by L-alanyl, L-leucyl, L-lysyl, alpha,L-glutamyl, gamma,L-glutamyl, L-asparaginyl, N-benzoyl-L-arginyl, N-carbobenzoxy-L-arginyl and N-benzoyl-L-phenylalanyl 2-naphthylamide. Among the substituted and unsubstituted peptide 2-naphthylamides L-prolyl-L-arginyl 2-naphthylamide is not hydrolysed in visible amounts; L-arginyl-L-arginyl, L-alanyl-L-arginyl-L-arginyl, L-alanyl-L-leucyl-L-tyrosyl, L-histidyl-L-seryl, L-seryl-L-tyrosyl and L-glycy-L-phenylalanyl 2-naphthylamide are metabolized in the renal and intestinal brush border; the reaction pattern obtained with N-carbobenzoxy-L-glycyl-L-glycyl-L-arginyl 2-naphthylamide differs from that of N-carbobenzoxy-L-arginyl 2-naphthylamide. In addition L-glycyl-L-prolyl, L-leucyl-L-alanyl, L-lysyl-L-alanyl and L-alanyl-L-phenylalanyl-L-prolyl 2-naphthylamide are also split in the lysosomes of many organs and the secretion granules of gland cells.     

Peptidasen II. Zur Lokalisation der Dipeptidylpeptidase IV (DPP IV). Histochemische und biochemische Untersuchung

Zusammenfassung Histochemisch wird die Dipeptidylpeptidase IV (DPP IV) mit Glycyl-prolyl(Gly-pro)-naphthylamiden als Substraten, stabilen und instabilen Diazoniumsalzen zur Simultankupplung und unterschiedlichen Puffern bei Ratten, Mäusen, Katzen, Meerschweinchen, Kaninchen, Hamstern und in menschlichen Dünndarmbiopsien nach verschiedenen Gewebevorbehandlungen untersucht. Die besten Resultate liefert 1,7–3,4 mM Gly-pro-4-methoxy-2-naphthylamid und 1 mg Fast Blue B/ml und mit Einschränkungen 0,025 ml hexazotiertes Neufuchsin/ml in 0,1 M Cacodylat- oder Phosphat-Puffer, pH 7,5, und frische Kryostatschnitte zum Nachweis der Gesamtaktivität der DPP IV und gefriergetrocknete Schnitte nach Celloidinmontage zur ortsgetreuen Lokalization des Enzyms. Schnitte von aldehydfixiertem Material eignen sich zur Untersuchung des Umsatzes von Gly-pro-naphthylamiden zwischen pH 5 und 7 mit hexazotiertem Neufuchsin oder p-Rosanilin in Lysosomen.Die DPP IV ist fest strukturgebunden und weist Spezies- und Organdifferenzen auf. Im allgemeinen kommt das Enzym in Kapillarendothelien, Sinusoidalzellen, Perineurium, Schalt- und Sekretrohrepithelien, Mikrovillizone von Darmkrypten und-zotten, Uterus, Tube, proximalen Nierentubuli sowie Nebenhodengang, Hepatocyten- und Lymphocytenmembran, Plasmalemm mehrschichtiger und Übergangsepithelien sowie in der Kapsel und im Interstitium zahlreicher Organe vor.Die biochemische Untersuchung der DPP IV wird mit 10 mM Gly-pro-2-naphthylamid in 0.1 M Cacodylat-Puffer, pH 7 durchgeführt und die Enzymaktivität fluorometrisch in Ratten- und Meerschweinchenorganen bestimmt. Die Befunde bestätigen und erweitern die auffälligen spezies- und organabhängigen Unterschiede des histochemischen DPP IV-Nachweises.Verglichen mit anderen Di- sowie Tripeptidyl- und Aminosäurenaphthylamiden deuten die Befunde darauf hin, daß es sich bei der DPP IV um eine Peptidylpeptidase handelt, die neben dem Kollagenabbau an anderen Stoffwechselvorgängen beteiligt ist.

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Histochemical and biochemical distribution of dipeptidylpeptidase IV (DPP IV)

Summary Fresh frozen, unfixed, chloroforme-acetone treated or freeze-dried cryostat sections or sections from aldehyde-fixed blocks of tissue were tried for the histochemical investigation of dipeptidylpeptidase IV (DPP IV) with l-glycyl-l-prolyl(gly-pro)-naphthylamides as substrates and stable or unstable diazonium salts for simultaneous coupling and various buffers, pH 5–7.5 in rats, mice, guinea-pigs, cats, rabbits, hamsters and human enterobiopsies. The best results are obtained with 1.7–3.4 mM gly-pro-4-methoxy-2-naphthylamide and 1 mg Fast Blue B/ml or (with some limitations) 0.025 ml hexazotized new fuchsine/ml in 0.1 M cacodylate or phosphate buffer, pH 7.5 and unfixed sections for the demonstration of the total activity of DPP IV and freeze-dried celloidin-mounted cryostat sections for the precise localization of the enzyme or the detection of lysosomes, Golgi apparatus and secretion granules; sections from aldehyde fixed tissue blocks are only suitable to study the lysosomal hydrolysis of gly-pro-naphthylamides between pH 5 and 7 when hexazotized p-rosaniline or new fuchsine are employed.DPP IV is firmly bound to structures and shows species- and organ-dependent differences. In general, the enzyme occurs in the capillary endothelium, sinusoidal cells, perineurium, epithelial cells of intercalated and striated ducts, microvillous zone of intestinal crypts and villi, uterus, Fallopian tube, ductus epididymis and proximal renal tubules, hepatocyte and lymphocyte membrane, plasmalemma of pseudostratified and transient epithelia and in the capsules and interstitium of many organs. These sites of activity can be completely inhibited by diisopropyl fluorophosphate and partially by Pb²⁺; Mg²⁺, Mn²⁺, Co²⁺ EDTA are without any influence. Phenantrolin may activate DPP IV.The biochemical assay works with 10 mM gly-pro-2-naphthylamide in 0.1 M cacodylate buffer, pH 7; the enzyme activity is determined fluorometrically in guinea-pig and rat organs; the data confirm and enlarge the species-and organ-dependent differences revealed by histochemistry.Compared with other dipeptide as well as tripeptide and amino acid naphthylamides the results obtained for DPP IV suggest a peptidylpeptidase which seems to be involved in other metabolic processes beside the degradation of collagen.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft (SFB 105)     

Tetrazolium methods for the histochemical investigation of hydrolases (author's transl)]

Using freeze-dried or sections from fresh-frozen or aldehyde-fixed material nitro BT (NBT), tetranito BT (TNBT), distyryl nitro BT (DS-NBT), thiocarbamyl nitro BT (TC-NBT) or benzothiazolylstyrylphthalhydrazidyl tetrazolium chloride (BSPT) were tested as auxiliary reagents for the localization of glycosidases, phosphatases and non-specific esterases with indoxyl substrates in rat tissues. By means of NBT or TNBT as a tetrazolium salt acid beta-D-galactosidase, beta-D-N-acetylglucosaminidase, acid phosphatase, neuraminidase and non-specific esterase can only be localized at the cellular level; a more precise localization is possible for lactase-beta-D-glucosidase in the intestinal brush border, and the best results are obtained in the demonstration of alkaline phosphatase; among all methods described previously the tetrazolium procedure with TNBT is the method of choice for the light microscopic localization of this enzyme. Reverse data are observed with BSPT as a tetrazolium salt; then, all acid and neutral hydrolases can be exactly localized in lysosomes, secretion granules, cytoplasm and/or microvilli of many cells and tissues provided BSPT-formazan is stabilized by osmification. Furthermore, this procedure enables the reliable ultracytochemical demonstration of these enzymes. However, in the case of alkaline phosphatase only sites with high enzyme activity reveal a positive reaction. -DS- and TC-NBT are inferior to NBT, TNBT or BSPT.     

Ultrastructural cytochemistry of p-N,N-dimethylamino-beta-phenethylamine (DAPA) oxidation reactions.

The ultracytochemical localization of amine oxidase (AO) activity is demonstrated with a new substrate, p-N,N-dimethylamino-beta-phenethylamine (DAPA). DAPA was designed to yield a stronger reducing agent on oxidation by monoamine oxidase (MAO) than is obtained from the MAO substrate, tryptamine, upon oxidation. Thus MAO and possibly other oxidase(s) can be demonstrated with DAPA and the tetrazolium salt, 2-(2'-benzothiazolyl)-5-styryl-3-(4'-phthalhydrazidyl) tetrazolium chloride (BSPT). The latter is a nonosmiophilic tetrazolium salt which is reduced to an osmiophilic formazan. In addition, DAPA itself demonstrates AO activity ultracytochemically with and without BSPT. We speculate that either oxidative polymerization of DAPA or Schiff's base formation with protein after aldehyde formation is responsible for the latter reaction, which is made permanent for ultracytochemical localization by osmication at a later step. DAPA oxidation reaction products are demonstrated in guinea pig kidney, specifically in the endoplasmic reticulum, nuclear envelope and mitochondrial outer compartments and cristae. Differences in reaction product characteristics and localization in relation to formaldehyde fixation and the localization of reaction product in mitochondrial cristae, as well as outer compartments, suggest that DAPA oxidation is mediated through one or more MAOs and possible other oxidases.     

Light-microscopic histochemistry of non-specific alkaline phosphatase using lanthanide-citrate complexes

New lanthanide methods for the histochemical detection of non-specific alkaline phosphatase in the light microscope are described and compared with already existing techniques for the light microscopical demonstration of this enzyme. To avoid formation of insoluble lanthanide hydroxide at alkaline pH citrate complexes with the capture ions cerium, lanthanum and didymium were used. A molar ratio of 11 mM citrate/14 mM capture reagent is proposed. For preincubated sections, pretreatment in chloroform-acetone and fixation in glutaraldehyde, for non-preincubated sections fixation in glutaraldehyde yielded the best results. 4-Methylumbelliferyl and 5-Br-4-Cl-3-indoxyl phosphate were found to be the most suitable substrates. For routine purposes 4-nitrophenyl, 1-naphthyl, 2-naphthyl and 2-glycerophosphate were also sufficient; naphthol AS phosphates were inferior but still suitable. After incubation for 5-60 min at 37 degrees C lanthanide phosphate was converted into lead phosphate which was visualized as lead sulfide. At pH 9.2-9.5 enzyme activity was demonstrated at many sites such as intestinal, uterine, placental, renal and epididymal microvillous zones, plasma membranes of arterial, sinus and capillary endothelial cells, vaginal and urethral epithelium, smooth muscle cells, myoepithelial cells as well as excretory duct cells of salivary and lacrimal glands and in secretory granules of laryngeal glands. In comparison with Gomori's calcium, Mayahara's lead, Burstone's and Pearse's azo-coupling, McGadey's tetrazolium salt and Gossrau's azoindoxyl coupling technique the lanthanide methods detected alkaline phosphatase activities at identical or additional sites depending on the respective procedure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Menadiol diphosphate, a new substrate for non-specific alkaline phosphatase in histochemistry and immunohistochemistry.

Menadiol diphosphate was introduced as a new substrate for nonspecific alkaline phosphatase, following a search for new and less expensive substrates, which give a more sensitive response and are easily synthesized in the laboratory. Menadiol released by phosphatase action can be assayed by its reduction of tetrazolium salts, or it can be coupled with diazonium salts; alternatively, the phosphate can be trapped by metal ions. The synthesis and purification of menadiol diphosphate are described, and it was shown to be sufficiently stable for qualitative and semiquantitative histochemistry, as well as for the immunohistochemistry of enzymes and cytoskeletal proteins with nonspecific alkaline phosphatase as the enzyme label. For qualitative as well as semiquantitative histochemistry and immunohistochemistry, the best results were obtained by applying the method with nitro-blue tetrazolium (NBT) to acetone-chloroform pretreated cryostat sections. Tetranitro-blue tetrazolium (TNBT), benzothiazolylphthalhydrazidyl tetrazolium (BSPT) and various diazonium salts were less suitable. Fast Blue BB and VB produced satisfactory results. Ce3+ ions and the DAB-Ni-H2O2 procedure yielded better results than Ca2+ ions in the Co-(NH4)2S visualization method. The NBT method with menadiol diphosphate is superior to existing methods employing azo, azoindoxyl or tetrazolium salts and to metal precipitation methods. The Ce3+ technique and the NBT/menadiol diphosphate method give similar results, and appear to be of equal value. In qualitative histochemistry and immunohistochemistry the NBT/menadiol diphosphate method resulted in higher quantities of precisely localized stain. Semiquantitative histochemistry with minimal incubation revealed more favorable kinetics for the menadiol diphosphate method, especially when using NBT.     

Light-microscopic histochemistry of non-specific alkaline phosphatase using lanthanide-citrate complexes

Summary New lanthanide methods for the histochemical detection of non-specific alkaline phosphatase in the light microscope are described and compared with already existing techniques for the light microscopical demonstration of this enzyme. To avoid formation of insoluble lanthanide hydroxide at alkaline pH citrate complexes with the capture ions cerium, lanthanum and didymium were used. A molar ratio of 11 mM citrate/14 mM capture reagent is proposed. For preincubated sections, pretreatment in chloroform-acetone and fixation in glutaraldehyde, for non-preincubated sections fixation in glutaraldehyde yielded the best results. 4-Methylumbelliferyl and 5-Br-4-Cl-3-indoxyl phosphate were found to be the most suitable substrates. For routine purposes 4-nitrophenyl, 1-naphthyl, 2-naphthyl and 2-glycerophosphate were also sufficient; naphthol AS phosphates were inferior but still suitable. After incubation for 5–60 min at 37° C lanthanide phosphate was converted into lead phosphate which was visualized as lead sulfide. At pH 9.2–9.5 enzyme activity was demonstrated at many sites such as intestinal, uterine, placental, renal and epididymal microvillous zones, plasma membranes of arterial, sinus and capillary endothelial cells, vaginal and urethral epithelium, smooth muscle cells, myoepithelial cells as well as excretory duct cells of salivary and lacrimal glands and in secretory granules of laryngeal glands. In comparison with Gomori's calcium, Mayahara's lead, Burstone's and Pearse's azo-coupling, McGadey's tetrazolium salt and Gossrau's azoindoxyl coupling technique the lanthanide methods detected alkaline phosphatase activities at identical or additional sites depending on the respective procedure. However, in contrast to the other methods especially the cerium citrate procedure yielded a more precisely localized and more stable reaction product, can be used with all available alkaline phosphatase substrates including those up till now less suitable or unsuitable for light microscopic alkaline phosphatase histochemistry.     

Simultaneous Demonstration of Nonspecific Esterase and Chloroacetate Esterase in Human Blood Cells

A new cytochemical method is described for the simultaneous demonstration of nonspecific esterase in monocytes and chloracetate esterase in granulocytes. The procedure uses both alpha-naphthyl butyrate and naphthol AS-D chloroacetate as substrates and hexazotized pararosaniline as the coupler. The enzyme reaction products are highly chromogenic and their localization is precise. This method is potentially useful for the accurate diagnosis of the acute monocytic leukemias. Its advantages and limitations are also discussed.     

Simultaneous demonstration of nonspecific esterase and chloroacetate esterase in human blood cells

A new cytochemical method is described for the simultaneous demonstration of nonspecific esterase in monocytes and chloracetate esterase in granulocytes. The procedure uses both alpha-naphthyl butyrate and naphthol AS-D chloroacetate as substrates and hexazotized pararosaniline as the coupler. The enzyme reaction products are highly chromogenic and their localization is precise. This method is potentially useful for the accurate diagnosis of the acute monocytic leukemias. Its advantages and limitations are also discussed.     

Menadiol diphosphate,a new substrate for non-specific alkaline phosphatase in histochemistry and immunohistochemistry

Summary Menadiol diphosphate was introduced as a new substrate for nonspecific alkaline phosphatase, following a search for new and less expensive substrates, which give a more sensitive response and are easily synthesized in the laboratory. Menadiol released by phosphatase action can be assayed by its reduction of tetrazolium salts, or it can be coupled with diazonium salts; alternatively, the phosphate can be trapped by metal ions. The synthesis and purification of menadiol diphosphate are described, and it was shown to be sufficiently stable for qualitative and semiquantitative histochemistry, as well as for the immunohistochemistry of enzymes and cytoskeletal proteins with nonspecific alkaline phosphatase as the enzyme label. For qualitative as well as semiquantitative histochemistry and immunohistochemistry, the best results were obtained by applying the method with nitro-blue tetrazolium (NBT) to acetone-chloroform pretreated cryostat sections. Tetranitro-blue tetrazolium (TNBT), benzothiazolylphthalhydrazidyl tetrazolium (BSPT) and various diazonium salts were less suitable. Fast Blue BB and VB produced satisfactory results. Ce³⁺ ions and the DAB−Ni−H₂O₂ procedure yielded better results than Ca²⁺ ions in the Co−(NH₄)₂S visualization method. The NBT method with menadiol diphosphate is superior to existing methods employing azo, azoindoxyl or tetrazolium salts and to metal precipitation methods. The Ce³⁺ technique and the NBT/menadiol diphosphate method give similar results, and appear to be of equal value. In qualitative histochemistry and immunohistochemistry the NBT/menadiol diphosphate method resulted in higher quantities of precisely localized stain. Semiquantitative histochemistry with minimal incubation revealed more favorable kinetics for the menadiol diphosphate method, especially when using NBT. Supported by the Alexander von Humboldt-Stiftung and the Deutsche Forschungsgemeinschaft (Sfb 174)     

Histochemical detection of α-d-glucosidases and their molecular forms with 5-Br-4-Cl-3-indoxyl-α-d-glucoside

Summary 5-Br-4-Cl-3-Indoxyl--d-gluco(pyrano)side was found to be the most suitable synthetic substrate for the demonstration of -d-glucosidases in situ. Using an azoindoxyl procedure with hexazotized pararosaniline or new fichsine at pH 5 in freeze-dried celloidine-mounted cryostat sections acid -d-glucosidase (EC 3.2.1.20) was shown for the first time in lysosomes of many cells of fetal and adult rat, mouse, guinea-pig, marmoset and human organs. At pH 6.5, in chloroform-acetone pretreated cryostat sections plasma membrane -d-glucosidases were shown in the brush border of enterocytes of the small and large intestine, in the brush border of proximal renal tubule cells and in the stereocilia of the epididymal duct. In an indigogenic procedure with ferricyanide/ferrocyanide as redox catalysator plasma membrane -d-glucosidases were depicted as well as with the azo-indoxyl method; the demonstration of the acid -d-glucosidase was inferior to that achieved with the azo-indoxyl procedure. Using tetrazolium salts as capture reagent intracellular localization was unsatisfactory. In enterocytes, a localization in the Golgi apparatus was shown by the azo-indoxyl procedure only. Analytical isoelectric focusing revealed organ-dependent differences of plasma membrane and lysosomal -d-glucosidases. Compared with the already existing methods the azo-indoxyl and indigogenic procedures are by far the most suitable techniques.Supported by the German Research Foundation (Sfb 174) and the BMFT (Project CMT 35)