Localization of neurotensin-immunoreactive cells in the small intestine of man and various mammals.

Antibodies against synthetic bovine neurotensin were raised in rabbits and used to demonstrate neurotensin-immunreactive cells by immunohistochemical methods. In the jejunum and ileum of all species investigated (man, dog, monkey, cat, rabbit, sheep, rat, mouse, hamster, chinese hamster, gerbil, pig and guinea pig) cells were present in the mucosa, which reacted specifically with antineurotensin serum using the indirect immunofluorescence and peroxidase-antiperoxidase methods. In the monkey Tupaia the distribution of neurotensin-immunoreactive cells was examined by investigating serial sections through the entire gastro-entero-pancreatic (GEP) endocrine system, again showing most neurotensin-immunoreactive cells in the jejunum and ileum. The functional role of the presence of neurotensin immunoreactivity in the gut is discussed.     

Localization of neurotensin-immunoreactive cells in the small intestine of man and various mammals

Summary Antibodies against synthetic bovine neurotensin were raised in rabbits and used to demonstrate neurotensin-immunreactive cells by immunohistochemical methods. In the jejunum and ileum of all species investigated (man, dog, monkey, cat, rabbit, sheep, rat, mouse, hamster, chinese hamster, gerbil, pig and guinea pig) cells were present in the mucosa, which reacted specifically with antineurotensin serum using the indirect immunofluorescence and peroxidase-antiperoxidase methods. In the monkey Tupaia the distribution of neurotensin-immunoreactive cells was examined by investigating serial sections through the entire gastro-entero-pancreatic (GEP) endocrine system, again showing most neurotensin-immunoreactive cells in the jejunum and ileum. The functional role of the presence of neurotensin immunoreactivity in the gut is discussed.Supported by the German Research Foundation     

Use of substance P fragments to differentiate substance P receptors of different tissues

The C- and N-terminal fragments of substance P were compared to the parent molecule with respect to their ability to: (a) contract the isolated guinea pig ileum, (b) induce salivation in the rat, (c) excite single cat dorsal horn neurones, and (d) induce scratching by intracranial injections in mice. C-terminal fragments as small as the heptapeptide were potent SP agonists on all assay systems. C-terminal fragments containing five amino acids or less were, at most, only weakly active. The C-terminal hexapeptide was a potent SP receptor stimulant on the isolated guinea pig ileum and, when directly applied by microiontophoresis, on cat dorsal horn neurons. However, the same compound was only 2-5% as potent as substance P in eliciting salivation and scratching in vivo, an indication that this fragment may be especially labile to enzymatic degradation. N-terminal fragments were totally inactive on the isolated guinea pig ileum. On the rat salivation and central nervous system assays, however, N-terminal fragments were capable of weak SP-like activity. It is concluded that SP receptors exist in multiple forms which we have labelled SP1 and SP2 receptors for those insensitive or sensitive to N-terminal fragments, respectively.     

Neuromedin N: a novel neurotensin-like peptide identified in porcine spinal cord

A novel neurotensin-like peptide, designated neuromedin N, has been isolated from porcine spinal cord by using a bioassay for a stimulant effect on guinea pig ileum. By microsequencing, the amino acid sequence of the peptide has been determined to be Lys-Ile-Pro-Tyr-Ile-Leu, which is found to be quite homologous to the COOH-terminal sequence of neurotensin. This structure has been confirmed by synthesis. Neuromedin N exhibits a contractile activity on guinea pig ileum and induces a hypotensive response in the rat similar to that with neurotensin. These findings suggest that neuromedin N may be a new neuromediator or hormone with a specific spectrum of biological activity.     

Immunohistochemical localization of neurotensin in endocrine cells of the gut

Summary Endocrine cells displaying neurotensin immunoreactivity are found scattered in the jejuno-ileum of all mammals studied, including man. They are rather scarce in rat, guinea pig, rabbit and pig and fairly numerous in cat, dog and man. In most mammals the neurotensin cells predominate on the villi. Only in the dog are they more numerous in the crypts. In the chicken, neurotensin cells occur all along the intestinal tract. They are particularly numerous in the zone that joins the gizzard with the duodenum. The ontogeny of the neurotensin cells in the gut was studied in rats and chickens. In the rat, the cells are first observed in the jejuno-ileum immediately before birth. The adult frequency is reached 4–5 days later. In the chicken, neurotensin cells first appear in the colon in the 18 day old embryo and in the small intestine two days later (i.e. one or two days before hatching). A few days after hatching, the gut has achieved the adult number of neurotensin cells per unit area.     

Binding of [3H]Ro 5–4864 and [3H]PK 11195 to Cerebral Cortex and Peripheral Tissues of Various Species: Species Differences and Heterogeneity in Peripheral Benzodiazepine Binding Sites

The binding of [3H]PK 11195 and [3H]Ro 5-4864 to membrane preparations from cerebral cortex and peripheral tissues of various species was studied. [3H]PK 11195 (0.05-10 nM) bound with high affinity to rat and calf cerebral cortical and kidney membranes. [3H]Ro 5-4864 (0.05-30 nM) also successfully labeled rat cerebral cortical and kidney membranes, but in calf cerebral cortical and kidney membranes, its binding capacity was only 3 and 4%, respectively, of that of [3H]PK 11195. Displacement studies showed that unlabeled Ro 5-4864, diazepam, and flunitrazepam were much more potent in displacing [3H]PK 11195 from rat cerebral cortex and kidney membranes than from calf tissues. The potency of unlabeled Ro 5-4864 in displacing [3H]PK 11195 from the cerebral cortex of various other species was also tested, and the rank order of potency was rat = guinea pig greater than cat = dog greater than rabbit greater than calf. Analysis of these displacement curves revealed that Ro 5-4864 bound to two populations of binding sites from rat and calf kidney and from rat, guinea pig, rabbit, and calf cerebral cortex but to a single population of binding sites from cat and dog cerebral cortex. Using [3H]PK 11195 as a ligand, the rank order of binding capacity in cerebral cortex of various species was cat greater than calf greater than guinea pig greater than rabbit greater than dog greater than rat, whereas when [3H]Ro 5-4864 was used, the rank order of binding capacity was cat greater than guinea pig greater than rat greater than rabbit greater than calf greater than dog.     

Characterization of neurokinin receptors in various isolated organs by the use of selective agonists

The three mammalian neurokinins, substance P, neurokinin A and neurokinin B, as well as some agonists selective for their respective receptors, NK-P, NK-A and NK-B, were tested in a variety of pharmacological preparations in order to evaluate if the biological responses of the various tissues were mediated by single or multiple receptor types. Previous observations that the dog carotid artery, the rabbit pulmonary artery and the rat portal vein are selective preparations respectively for SP, NKA and NKB were confirmed in the present study by showing that only the respective selective agonists were active on these tissues. Multiple functional sites were demonstrated in intestinal tissues (guinea pig ileum, rat duodenum), which apparently contain the three neurokinin receptors. A large number of NK-P, together with some NK-A receptor sites were found in the guinea pig and rat urinary bladder. Similarly, the guinea pig trachea and the rabbit mesenteric vein contain NK-A and NK-P functional sites. Rat and rabbit vas deferens stimulated electrically respond as typical NK-A preparations, since they are almost insensitive to SP or NKB selective agonists. A mixture of NK-A and NK-B receptor sites has been shown to be present in the hamster urinary bladder: dog and human urinary bladder definitely contain NK-A receptors and the dog bladder also some NK-P functional sites.     

Pharmacological actions of tentacle extract of the jellyfish, Acromitus rabanchatu, occurring in the Bay of Bengal

Tentacle extract of A.rabanchatu, produced a fall of blood pressure in cat, rat and guinea pig. Hypotension produced in cat remained unantagonized by blockers of acetylcholine, histamine and 5-HT. On isolated guinea pig heart, the extract significantly reduced the rate and amplitude of contraction leading to irreversible cardiac arrest. In cats and rats, the respiratory rate and amplitude was decreased significantly and resulted in temporary apnoea. The extract also produced vasoconstriction in perfused rat hindquarter preparation and increased cutaneous capillary permeability. The extract produced contraction in several isolated smooth muscle preparations. Contraction on guinea pig ileum was partly antagonized by atropine and cyproheptadine. On isolated rat phrenic nerve diaphragm and chick biventer cervicis, the extract produced irreversible blockade of the electrical stimulation-induced twitch responses. Haemolytic and myonecrotic activity was exhibited by the extract. LD50 was found to be 7.7 mg/kg (iv, mice).     

Radioactive analogs of neurotensin. II. Preparation of tritiated neurotensin from a synthetic multi-unsaturated derivative

In this second paper on the synthesis of neurotensin analogues as precursors for radiolabelling, solid phase synthesis of two polyunsaturated peptides, [Dah6, delta Pro7,10]-neurotensin and acetyl-[delta Pro10]-neurotensin-(8-13), are described. The first one contains one triple bond and two double bonds susceptible to tritiation in the same molecule, the second one contains one double bond in the shortest sequence having neurotensin activity. The C-terminal residue, Boc-Leu, was esterified on the chloromethyl-resin by its cesium salt. For the other amino acids a double coupling was carried out, the first one with dicyclohexylcarbodimide and the second one with the amino acid hydroxybenzotriazole ester. Acylation of the second amino acid, on the resin, presented some difficulties to achieve completeness and several acetylations and benzoylations had to be performed in order to block the last 4 per cent of free amines. It seems that these difficulties are related to some batches of chloromethyl-resin. Incorporation of both acetylenic lysine, N alpha-Boc-N epsilon-Z-L-2,6-diamino-4-hexynoic acid, whose synthesis is described, and N alpha-Boc-L-3,4-dehydroproline was without problems in this synthesis. After cleavage by hydrofluoric acid the crude peptides were purified by gel filtration on Bio-Gel P2 and ion exchange chromatography on carboxymethylcellulose (CM 52). [Dah6, delta Pro7,10]-neurotensin so obtained (51 per cent compared to starting Boc-Leu-resin) was in homogeneous form as characterized by amino acid analysis, thin layer chromatography in different systems and high performance liquid chromatography. The hydrogenation or tritiation product was identical with native neurotensin. Unsaturated derivative and neurotensin obtained after catalytic hydrogenation were as active as native neurotensin in inhibition of 125I-[Trp11]-neurotensin binding to rat brain synaptic membranes and in guinea pig ileum contractility test. Substitution of proline and lysine by their dehydro-derivatives did not affect the biological properties of neurotensin. The tritiated neurotensin (160-180 Ci/mmol) should be a good agent for biological characterization of neurotensin receptors and for investigation of the peptide metabolism.     

Neuromedin-N inhibits migrating myoelectric complex and induces irregular spiking in the small intestine of rats; comparison with neurotensin.

The effects of neuromedin-N on migrating myoelectric complexes in the small intestine of rats were studied. As neuromedin-N and neurotensin are structurally related peptides a comparison with neurotensin was made. Myoelectric activity was recorded by means of three bipolar electrodes implanted into the wall of the small intestine at 5, 15 and 25 cm distal to the pylorus. The peptides were administered as intravenous infusions to fasted conscious rats. Neuromedin-N at doses of 100-800 pmol kg-1 min-1 caused a dose-dependent disruption of the migrating myoelectric complexes and induced irregular spiking activity (n = 7, P less than 0.05). Neurotensin induced a similar response, but at doses of 1.0-8.0 pmol kg-1 min-1 (n = 5, P less than 0.05). Thus, on a molar basis, neuromedin-N appeared to be about 100-times less potent than neurotensin. Hexamethonium (20 mg kg-1 i.v.) inhibited the migrating motor complexes and induced quiescence, but did not block the effect of neuromedin-N at a dose of 800 pmol kg-1 min-1. Atropine (1 mg kg-1 i.v.) and mepyramine (2 mg kg-1 i.v.) did not affect the migrating motor complexes, nor did they block the effect of neuromedin-N. Simultaneous infusion of neuromedin-N and neurotensin in a 1:1 molar ratio at doses of 2 pmol kg-1 min-1 showed inhibition of the response to neurotensin in eight out of ten experiments. In conclusion, neuromedin-N changes the myoelectric activity in the small intestine from a fasting to a fed pattern.(ABSTRACT TRUNCATED AT 250 WORDS)     

Isolation, partial purification and pharmacodynamics of a slow contractile substance in the venom sac extract of the wasp Vespa cincta Fabr

The venom of V. cincta contains acetylcholine (ACh), histamine and 5-hydroxytryptamine (5-HT). Blockers of these agonists did not block completely the hypotensive and smooth muscle contractile activity of venom. On smooth muscle, there was a residual slow contraction. The active substance which produced this slow contraction was separated by solvent extraction, gel filtration and TLC. The purified material (which has been provisionally designated "Vecikinin") lowered cat, rat and guinea pig blood pressure, increased amplitude of cardiac contraction, and increased capillary permeability. Vecikinin contracted several smooth muscle preparations (rat uterus, rat ascending colon, guinea pig ileum, guinea pig colon and rat ileum), while relaxing rat duodenum. Its contractile activity was not lost on boiling, but acid or alkali-boiling reduced its contractile activity. It was inactivated on incubation with chymotrypsin and carboxypeptidase but not with trypsin, pepsin or leucine aminopeptidase. It is a peptide, appears to be of low molecular weight, and could be distinguished from substance P, angiotensin, bradykinin and hornet or wasp kinin.     

Speciesabhängigkeit der Monoaminoxydase-Aktivität in verschiedenem Lebensalter

Summary The monoamine oxidase activity in ten species (man, dog, cat, rabbit, guinea pig, rat, hamster, mouse, chicken, goose) was histochemically studied in the myocardium, liver, kidney and psoas muscle in newborn and older individuals.An age-dependent increase of monoamine oxidase activity is established in the liver and kidney of man, dog, cat, guinea pig and hamster. In the psoas muscle of the rat the monoamine oxidase activity is consistently weak. In the myocardium only the rat shows an increase with age.     

Comparative studies on the gastric glycopeptide in eleven animal species.

1. Glycopeptides in the stomachs of eleven mammalian species, including human, rabbit, horse, cow, pig, goat, sheep, dog, cat, guinea pig and rat were assayed by determining the carbohydrate content of materials which remained after proteolysis. 2. The glycopeptide content was higher in the mucosa than in the muscular layer including serosa, especially in the porcine stomach and the fourth stomachs of the ruminants than in the stomachs of any other animals. 3. The glycopeptide, which was stained with both alcian blue and PAS, was absent or sparingly present in the mucosae of the human, rabbit, horse stomachs and in the mucosae of the first to third stomachs of the cow, goat and sheep, whereas in the mucosae of the pig, dog, cat, guinea pig and rat stomachs and in the mucosae of the fourth stomachs of the cow, goat and sheep, it was found in noticeable extents.     

The relation between structure and function of bile ducts in man, some laboratory animals and the Adelie penguin.

The biliary trees of man, dog, cat, rabbit, rat, guinea pig and penguin were examined in histological sections and by latex casts. The trees of man, dog, and cat were similar with only minor differences. Tubulo-alveolar glands were present in all three species around large intrahepatic ducts and in large portal tracts there were zones of ductules (areas with many small bile ducts), surrounded by small vessels with no apparent relation to hepatocytes. Both these features were present in the guinea pig and tubulo-alveolar glands were present in the penguin liver. The biliary epithelium of the rat was comparatively simple but that of the rabbit appeared to be highly specialized. An estimation of the complexity of the biliary tree was obtained in the mammals by comparing the circumference of small portal venous branches with the circumference of the accompanying bile ducts, and obtaining a ratio. Man, dog, and cat had fewer and smaller bile ducts than the other species. The literature on the rate of formation and composition of bile in the species studied here was reviewed and it appears that the physiology of bile secretion can be related to the morphology of the biliary tree.     

Chinchilla "big" and "little" gastrins

Gastrin heptadecapeptides (gastrins I and II which differ in the presence of sulfate on the tyrosine of the latter) have been purified and sequenced from several mammalian species including pig, dog, cat, sheep, cow, human and rat. A 34 amino acid precursor ("big" gastrin), generally accounting for only 5% of total gastrin immunoreactivity, has been purified and sequenced only from the pig, human, dog and goat. Recently we have demonstrated that guinea pig (GP) "little" gastrin is a hexadecapeptide due to a deletion of a glutamic acid in the region 6-9 from its NH2-terminus and that GP "big" gastrin is a 33 amino acid peptide. The chinchilla, like the GP, is a New World hystricomorph. This report describes the extraction and purification of "little" and "big" gastrins from 31 chinchilla antra. Chinchilla "little" gastrin is a hexadecapeptide with a sequence identical to that of the GP and its "big" gastrin is a 33 amino acid peptide with the following sequence: (See text)     

Structure-activity studies of heptapeptide derivatives related to substance P, neurokinin A, B and other tachykinins on smooth muscles

Diverse C-terminal heptapeptide derivatives related to substance P, kassinin, physalaemin, neurokinin A and B were synthesized and the contracting activities on the guinea pig ileum as well as rat duodenum were compared. In the partial sequence of C-terminal of tachykinin peptides, -I-II-Phe-III-Gly-Leu-Met-NH2, the combination of amino acid residues at positions I and III have significant roles in contraction of smooth muscle. For the activation of rat duodenal muscle (SP-E), Asp(I) and aliphatic amino acid(III), and for guinea pig ileal muscle(SP-P), Gln(I) and aromatic amino acid(III) are essential. Moreover, guinea pig ileum is sensitive to a full sequence of neurokinin peptides.     

Pharmacological studies on the venomous spotted butterfish (Scatophagus argus Linn) sting extract on experimental animals

A sting of the fish S. argus, a venomous edible spotted butterfish, produces tremendous local pain, severe swelling, rise of body temperature, throbbing sensation etc. To establish the pharmacological activities of S. argus sting extract, the present investigation, was carried out on experimental animals. The LD50 of extract was found to be 9.3 mg/kg (iv) in male albino mice. The extract showed loss of sensation, urination and salivation in mice. It potentiated pentobarbitone induced sleeping time in male albino mice and produced hypothermia. Extract produced a fall of cat and guinea pig blood pressure, which was completely abolished by mepyramine. It produced a transient reduction of respiratory rate in rat, but decreased respiratory amplitude in cat, which was abolished after vagotomy. On isolated toad heart, the extract increased both the amplitude and rate of contraction. On isolated guinea pig heart, the sting extract decreased both the rate and amplitude of contraction leading to cardiac arrest, but it had no effect on isolated guinea pig auricle. The extract produced a reversible blockade of electrically induced twitch response of isolated chick biventer cervices preparation, but it had no effect on the isolated rat phrenic nerve diaphragm preparation. It produced a slow contractile response on isolated guinea pig ileum, rat uterus and rat fundal strip preparations but produced slow relaxation on isolated rat duodenum preparation. The contractile response on isolated guinea pig ileum and rat fundal strip was antagonised by SC19220. It did not produce any significant cutaneous haemorrhage in mice and did not produce any haemolysis on saline washed erythrocytes. The sting extract significantly increased capillary permeability of guinea pig dorsal flank and produced oedema in mice hind paw.     

Fine structure of atrial natriuretic peptide (ANP)-granules in the atrial cardiocytes in the hamster, guinea pig, rabbit, cat and dog.

In the hamster, guinea pig, rabbit, dog and cat, the right and left atria and ventricles were examined by immunohistochemistry, and the right auricular cardiocytes were studied by transmission electron microscopy. Moreover, ANP-granules in the cardiocytes were analyzed by ultrastructural morphometry. Immunohistochemically, the most intensely ANP-reactive cardiocytes were localized in the right auricle, particularly more prominent in the hamster and guinea pig than in the rabbit, dog and cat. The immunoreaction in the dog and cat was weaker than that in the rabbit. ANP-immunoreactivity was not detected in the ventricular myocardium of any of all species examined, but was occasionally observed in the subendocardium of the ventricular septum. Ultrastructurally, ANP-granules were localized principally in the perinuclear region associated with the Golgi apparatus and scattered throughout the sarcoplasmic layers. The Golgi apparatus of the cardiocytes was better developed in the hamster and guinea pig than in the rabbit, dog and cat. It was poorly-developed in the dog and cat. By ultrastructural morphometry, the number of granules was greatest in the hamster followed by the guinea pig, rabbit and dog or cat, in this order. On the other hand, the diameter of granules was largest in the guinea pig and reduced via the hamster to the rabbit. The diameter was significantly smaller in the dog than in the rabbit. The diameter of granules of the cat was lay between the rabbit and dog.     

Beta-endorphin. Biological activity of analogs containing dermorphin and dynorphin sequences: ileum and vas deferens assays

Biological activity of synthetic beta-endorphin (beta-EP) analogs containing dermorphin or dynorphin-A-(1-13) structure has been investigated using the guinea pig ileum and the vas deferens of the mouse, rat and rabbit. Replacement of NH2-terminal 1-7 segment of camel beta-EP [beta c-EP-(1-7)] with dermorphin caused a great increase in opiate potency of the analog. [Dermorphin (1-7)]-beta c-EP was 120 times more potent than beta c-EP in the guinea pig ileum assay, 49 times more potent in the mouse vas deferens assay; and only 4 times more potent in the rat vas deferens assay. Replacement of NH2-terminal 1-13 segment of human beta-EP [beta h-EP-(1-13)] with dynorphin-A-(1-13) caused an increase in opiate potency in both the guinea pig ileum and rabbit vas deferens assays, a complete loss of potency in the rat vas deferens assay, and no change in the mouse vas deferens assay. In comparison with dynorphin-A-(1-13), the hybrid peptide was less potent in the guinea pig ileum assay as well as in mouse and rabbit vas deferens assay. It is suggested that beta c-EP-(8-31) facilitates the dermorphin moiety to act on opiate mu and delta receptors but not on the epsilon receptor, while beta h-(14-31) reduces the action of dynorphin on mu, delta and kappa receptors.