Stoffwechsel und Bewegung

The physiology of movement and of metabolism involves concepts such as energetics, energy consumption and energy balance. Investigations on the mechanics of the swimming of water beetles, protozoans and fish, the jumping of grass-hoppers, or the flying of insects and humming birds present results and questions which indicate that satisfactory explanations require the application of methods and techniques of these two fields of research. A combination of both approaches and closer interdisciplinary cooperation is suggested.     

Redoxpotentiale und Stoffwechsel

Ohne ZusammenfassungMit 10 Abbildungen.Aus dem Hygienischen Institut der Universität Rostock (Direktor: Prof. Dr.Werner Kollath).     

Strahlung und Stoffwechsel

Zusammenfassung Bei der weißen Maus liegt die den Gasstoffwechsel beeinflussende Grenzwellenlänge der UV-Strahlung bei 0,33 (UV-B).Im UR-Bereich sind die Wellenlängen über 3,00 (langwelliges UR) wirksam.Die UR-Strahlung läßt sich nicht durch direkte Wärmeeinwirkung ersetzen.Der sichtbare Anteil des Spektrums hat keinen Einfluß auf den Stoffwechsel.Der Stoffwechsel wird nur bei einem bestimmten Verhältnis von UV-B zu langwelligem UR beeinflußt.Dieser Quotient muß zwischen 25,5 und etwa 300 liegen, um den Stoffwechsel zu senken.Die Größe der Stoffwechselsenkung scheint innerhalb dieser Grenzen vom Wert des Quotienten abhängig zu sein.Eine Stoffwechselbeeinflussung tritt nur auf, wenn UV und UR gleichzeitig geboten werden, während eine zeitlich getrennte Bestrahlung mit UV und UR, ganz gleich in welcher Reihenfolge, keine Reaktion ergibt.Sinkt die Intensität bei 10 min Bestrahlungszeit unter 2 W/cm², so wird der Stoffwechsel nicht mehr beeinflußt.Eine bei 10 min nicht mehr wirksame Intensität kann nach entsprechender Verlängerung der Bestrahlungszeit die Reaktion wieder auslösen.Ein Optimum in bezug auf Intensität und Bestrahlungsdauer wurde nicht gefunden.Die durch eine Bestrahlung erzielte Stoffwechselsenkung hält etwa 24–36 Std an. Da aber die Nachwirkung länger anhält, ergibt sich bei wiederholter Bestrahlung eine Akkumulation, die sich dann auch in einer länger andauernden Senkung des Stoffwechsels äußert.     

Stoffwechsel und Wachstum bei Scyphomedusen

Measurements on the rate of growth ofRhizostoma octopus conducted byThiel (1966) yielded an unusual shape of the graphically plotted growth curve. The close relation between rates of growth and metabolism suggested, as a first step, the investigation of the oxygen consumption of this jelly-fish especially as a function of body weight. In accordance with the high rate of growth, oxygen consumption related to wet weight does not decrease during growth and shows weight proportionality. The same seems to be true for specimens of the relatedCyanea andChrysaora species. The rate of oxygen consumption of Scyphomedusae is rather high. Related to the organic matter the oxygen consumption inRhizostoma amounts to 2077 mm³/g/h at 15° C. This value is much higher than in other invertebrates. The unusual growth curve ofRhizostoma octopus affords a revision of the growth types established byvon Bertalanffy (1942). His third growth type cannot be distinguished exactly from the first type and hence must be united with it. The observations onRhizostoma seem to indicate the existence of another third type, where the rate of growth increases with increasing body size.     

Stoffwechsel phenolischer Verbindungen in gesunden und Braunrost-infizierten Gersten- und Weizenvarietäten

Metabolism of phenolic compounds in healthy and brown rust-infected barley and wheat varieties
Infections with Puccinia isolates cause an accumulation of phenolic compounds both in resistant and susceptible isogenic lines of barley and wheat seedlings. The increased de novo biosynthesis of hydroxy-cinnamic and -benzoic acids is catalysed by the enzyme phenylalanine-ammonia-lyase (PAL) whose activity seems to be controlled not only by the substrate (phenylalanine) but also by the formed products (phenols). Depending on its actual physiological state every plant species shows as a reaction upon infection a typical behaviour. It is remarkable that healthy and rust-infected plants contain the same percentage of individual phenolic acids. An infection does not lead to an increase of individual hydroxycinnamic- or benzoic acids. There are only differences in quantity but no differences in quality. The pattern of phenolic acids seems to be largely genetically determined and formed according to the developmental stage of the plants. The hydroxycinnamic and -benzoic acids formed during the host-parasit-interactions seem to be, at least for the analysed combinations, more the consequence than the cause of resistance.     

Das Vorkommen, der Kreislauf und der Stoffwechsel des Jods

Ohne ZusammenfassungIst auch als Sonderausgabe erschienen.     

Der Stoffwechsel von Ascaris lumbricoides bei Oxybiose und Anoxybiose

Ohne Zusammenfassung     

Biosynthese und Stoffwechsel der chinolizidinalkaloide von Sophora alopecuroides

Administration of matrine-U-³H and sophocarpine-U-³H to Sophora alopecuroides seedlings shows that these compounds were incorporated into quinolizidine alkaloids such as matrine, sophacarpine, and their N-oxides, but not into sophoridine. It is suggested that there is no stereochemical conversion of alkaloids of matrine configuration into sophoridine by the plant. The incorporation of cadaverine-1,5-¹⁴C was so low that it cannot be regarded with certainty as a physiological precursor of the alkaloids. The N-oxides of matrine and sophocarpine were isolated and identified by their chromatographic and chemical properties.     

Der respiratorische Stoffwechsel von Calliphoridenlarven in Beziehung zu Temperaturadaptation und Regulation

The oxygen consumption of five larval stages of the Calliphoridae Callitroga macellaria, Lucilia cuprina, and Calliphora vicina was analysed at different temperatures. There are differences in temperature adaptation in these three species as well as in the feeding and non-feeding larvae of Callitroga.Within fixed limits of tolerance the reaction to changes in temperature is more intensive in feeding than in non-feeding larvae. A high metabolic rate is related to high levels of sensitivity to temperature changes.At particular temperatures oxygen consumption generally decreases with age. The results partly confirm the well-established fact that at the same temperature the metabolic rate of ‘cold’-adapted stages and species is relatively high as compared to ‘warm’-adapted ones.During the course of experiments oxygen consumption was frequently inconstant as can be seen by comparing the oxygen consumption of the first and second parts of the experiments, or more exactly, by regression analysis of the oxygen consumption rates throughout these experiments. Increasing and decreasing oxygen consumption depends on temperature adaptation which indicates regulatory processes.A method to determine standard temperature using measurements of respiratory metabolism is discussed.     

Resorption und Stoffwechsel von Glucose im Darmtrakt der Wanderheuschrecke Locusta migratoria

Absorption and metabolic fate of ¹⁴C-glucose after injection into mid-gut preparations from Locusta migratoria were studied in vitro. After 5 min nearly half of the total radioactivity had already passed into the incubation medium and in 2 hr there was an increase to 75 per cent. The radioactivity in the medium was found mainly in glucose and fructose, which were approximately equally labelled, and a minor part appeared in the organic acid and sugar phosphate fraction. This pattern of labelling changed drastically when non-radio active glucose was present in the incubation mixture. In these experiments an extensive synthesis of sucrose could be demonstrated.

Sucrose formation from UDP-¹⁴C-glucose by mid-gut homogenates was stimulated by fructose-6-phosphate.

The appearance of radioactivity in the contents of the gut and in the faeces was demonstrated in in vivo experiments after injection of ¹⁴C-glucose into the haemolymph.

Sugar concentrations in the haemolymph of locusts were measured after 24 hr starvation and after feeding. The levels of glucose, fructose, and sucrose were very low in the starving animals and increased ten- to twenty-fold after feeding. The trehalose concentrations remained high and relatively constant.

The activities of 18 enzymes of the intermediary metabolism were assayed in the fore-, mid-, and hindgut.     

Morphogenese und Stoffwechsel höherer Pflanzen unter dem Einfluß einiger Herbizide und Growth Retardants

Summary Effects of TIBA, 2,4-D, Flurenol and CCC upon growth, root formation, membrane permeability, content of nucleic acids and stability of the chromatin were investigated. The four substances showed little or no effect on growth of isolated plant segments, but TIBA, 2,4-D and CCC caused 25–30% inhibition of growth of whole pea seedlings even at low concentrations. Root formation is inhibited by TIBA, Flurenol and 2,4-D, but not by CCC. At concentrations >10^-4mol/l all the substances reduced the permeability of the plasma lemma, at lower concentrations only CCC and Flurenol still reduced permeability of the plasma lemma. The ratio RNA/DNA was decreased by TIBA, 2,4-D and Flurenol but it was increased by CCC. The Tm-value of isolated pea-chromatin was lowered by treatment with CCC and elevated by treatment with TIBA, 2,4-D and Flurenol can decrease or increase the Tm of isolated chromatin depending on their concentration. The results have shown that even very low concentrations of herbicides and growth retardants are able to induce metabolic alterations with partly unknown consequences.     

Untersuchungen an der Niere des Siebenschläfers (Glis glis L.) im Winterschlaf und im sommerlichen Wachzustand

Zusammenfassung Nierenglomerula junger Siebenschläfer (Glis glis L.) wurden elektronen-mikroskopisch vor Beginn der ersten Winterschlafperiode untersucht. Dabei stellte sich eine normale Ultrastruktur der Glomerulumschlingen heraus. Von kleineren Unregelmäßigkeiten abgesehen, wurden keine verdickten Basalmembranen gefunden (Durchmesser ca. 1000–1200 Å).Früher veröffentlichte Befunde von Verdickungen der glomerulären Basalmembran bei Winterschläfern auch während der aktiven Wachperiode (Amon et al., 1965; Zimny u. RigaMer, 1966) beruhen offenbar auf fixierten und irreversiblen Struktur- und Permeabilitätsveränderungen als Folgeerscheinungen der Hibernation. Über seinen physiologischen Charakter hinaus enthüllt damit der Winterschlaf auch deutliche pathologische Züge.

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Summary Renal glomerula of the young dormouse (Glis glis L.) were investigated previous to first hibernation by means of electron microscopy. The observations revealed normal ultrastructural proportions of the glomerular loops, particularly a non-thickened basement membrane of 1000–1200 Å in diameter.The formerly published findings of glomerular basement membrane thickening of hibernators even during non-hibernating period (Amon et al., 1965; Zimny and Rigamer, 1966) thus are based on fixed and irreversible structural and permeability changes as a result of hibernation. Hence hibernation discloses distinct pathological features beyond the physiological character of its state.

     

Die Kieselsäure im Stoffwechsel von Cyclotella cryptica Reimann,Lewin und Guillard

Ohne ZusammenfassungAuszug aus der Dissertation der Mathem.-Naturw. Fakultät der Universität Göttingen (1965): D. Werner: Die Kieselsäure im Stoffwechsel von Thalassiosira fluviatilis Hust. Der verwendete Stamm wurde inzwischen auf Grund der elektronenmikroskopischen Zellstruktur als Cyclotella cryptica erkannt (vgl. Reimann, Lewin u. Guillard, 1963).     

Der Stoffwechsel heterotropher Flagellaten

Zusammenfassung Die vorstehenden Ausführungen geben ein Bild von der Entwicklung des vorliegenden Forschungszweiges. Dargelegt wird, daß infolge der in letzter Zeit festgestellten Bedeutung von Wirkstoffen für das gesamte Ernährungsproblem alle bisherigen Ergebnisse wankend geworden sind, so daß eine Neuuntersuchung notwendig ist. Die Bedeutung der Art der versuchsanstellung für das Ergebnis wurde dargelegt und die eigene Methodik geschildert.Aufgabe der nächsten Untersuchungen ist die Feststellung der Bedeutung einiger Faktoren für den Kohlenstoff- und Stickstoffwechsel. Eine Literaturübersicht wird am Schluß der Arbeitenreihe gegeben werden.Die früheren Arbeiten des Verfassers sind unter dem Namen Ondratschek erschienen.