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1.
Summary It has been demonstrated by cytophotometric measurements of the DNA-content in glial- and nerve cells of the snailsHelix pomatia (Stylommatophora) andPlanorbarius corneus (Basommatophora) that the giant nuclei of nerve cells in the central ganglia contain more than tens of thousands of DNA compared with sperm nuclei. According to the DNA-content of sperms (=n), the values for glial cells are between 2n and 4n for both species.

Herrn Prof. Dr. W.Dittrich, Institut für Strahlenbiologie der Universität Münster, danke ich für die Möglichkeit, am UMSP I arbeiten zu dürfen; Frl. A.Stipproweit danke ich für sorgfältige technische Assistenz.  相似文献   

2.
Summary The incorporation of tritiated glucose into the ovary of honey bee queens was studied by autoradiography. During the last stages of oogenesis, the synthesis of respectable amounts of glycogen was found in the reticuloplasm of the developing eggs. The follicle epithelium and also the nurse cells only appeared more lightly and transitory labelled at medium stages. An hypothesis was established concerning an antagonism of protein and polysaccharide formation in the cytoplasm corresponding to the rather late occurrence of glycogen in insect oogenesis.  相似文献   

3.
Summary The incorporation of tritiated uridine into the follicular epithelium of degenerating oocytes of the zebrafish,Brachydanio rerio, was studied by radio-autography. After incubation times from 1–12 h, the labelling of the follicular epithelial cells of degenerating oocytes was several times higher than in normal developing follicles. This indicates an increase of RNA-synthesis, probably necessary for the formation of lytic enzymes.  相似文献   

4.
Summary Microchromatography of dansylated substances was used to estimate the serotonin content of the penis retractor muscle (PRM) ofHelix pomatia. Pharmacological data in connection with the biochemical results suggest that 5-HT plays a role in the regulation of the mechanical activity of the PRM.  相似文献   

5.
Summary After application of cholesterol-3H in ligated abdomina of 5th larva stages of the caterpillarMamestra brassicae ecdyson-3H and ecdysteron-3H was demonstrated in the abdomina 6 days after injection. The results show that in this case the synthesis of the moulting hormones from cholesterol occurs without participation of the prothoracic glands.  相似文献   

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Summary InHelix pomatia L. the overlapping neuronal network was found to regulate the visceral functions (e.g. cardiorenal, respiratory and genital functions). The neural network is organized around the multifunctional interneurons, which take part in forming both afferent and efferent pathways. The interneurons are sensitive to a wide range of neurotransmitters or transmitter candidates including low molecular weight substances (ACh, 5HT, DA, octopamine, glutamate) and several oligopeptides. In this system both selection of information and modification of membrane properties (for example habituation) are carried out by a combination of simultaneously liberated active agents.  相似文献   

8.
Résumé La composition de l'urine du pulmoné terrestreStrophocheilus oblongus musculus, spécialement le taux de l'urée, est un reflet des différences du contenu protéique des aliments. Ce fait confirme que le fonctionnement du rein des mollusques et des vertébrés est semblable.  相似文献   

9.
Summary Changes in water, sodium, and potassium excretion following administration of synthetic oxytocin (Syntocinon)—alone or in combination with acetazolamide— resemble the changes that occur after an equivalent dose of neurohypophysial extract containing oxytocin. Since the action of Syntocinon on water and sodium excretion is manifest when carbonic anhydrase in kidney tissue is fully inhibited by acetazolamide, it may be assumed that the mechanism whereby Syntocinon increases sodium excretion is independent of carbonic anhydrase. Oxytocin does not affect ultrafiltration in the glomeruli (Krause 4) and would therefore appear to modify the reabsorption or excretion process in the tubuli.  相似文献   

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11.
Summary Kinetin (6-furfurylaminopurine) is rapidly absorbed byLemna minor L. 3 · 10–8 M/ml medium cause an immediate but temporary stimulation of RNA and protein synthesis during the first hour of the treatment. The following excessive accumulation of starch is considered to be more or less a direct consequence of a disturbed RNA and protein metabolism.  相似文献   

12.
G B Stefano  I Vadasz  L Hiripi 《Experientia》1979,35(10):1337-1338
The present study demonstrates that the potent opiate antagonist, naloxone can selectively block the DA induced inhibition of the bursting activity pattern of the RPal or Br-type neuron. The dopamine inhibitory affect can also be blocked by haloperidol, a established dopamine receptor blocker.  相似文献   

13.
Summary Synergistic effects of TA on gibberellin-dependent reactions in spermatophytes are not detectable in gametophytes of the fernAnemia phyllitidis where gibberellin substitutes for antheridiogens with regard to induction of male sexual organs and dark germination. In this archegoniate TA caused a significant reduction in growth rate and morphogenesis of the gametophytes, inhibitions that were not abolished by simultaneous application of gibberellin.  相似文献   

14.
Summary Evidence for the absolute configuration of (-)-2-dehydroemetine (IV) is presented.

Über die Darstellung der in dieser Mitteilung erwähnten vier optisch aktiven 2-Dehydroemetin-Isomeren und das Resultat ihrer chemotherapeutischen Untersuchung wird in Helv. chim. Acta ausführlich berichtet werden.  相似文献   

15.
Summary A dimorphic pair of chromosomes was found among the macrochromosomes in mitosis of females ofVipera berus L. It corresponds to a pair of medium-sized chromosomes in the male. The conclusion is drawn that females are heterogametic (ZW-type), males being homogametic (ZZ-type). Similar observations were made inVipera aspis L.,Natrix natrix L., andNatrix maura L.  相似文献   

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Summary In AlCl3-injected shell-repairing snails,Helix pomatia L., the Al-associated decrease of the weights of the shell-repair membranes was unrelated to the Al-concentration in the membranes. In the haemolymph the concentration of Al was related to the dose of injected Al, while the concentration of Ca was increased by the highest Al-dose only. No phosphate was detected in either controls or Al-injected snails. It is concluded that Al inhibits the growth of the CaCO3-crystals by mechanisms other than incorporation in, or adsorption to, the crystals.  相似文献   

18.
Riassunto Una popolazione diCobitis taenia, specie considerata sinora gonocorica, é risultata essere ermafrodita non bilanciato cioé con alta variabilità sessuale, comprendente ermafroditi successivi proterandrici e femmine. La presenza di maschi puri non é stata ancora dimostrata.

This work was supported by a financial grant from the Italian C.N.R.  相似文献   

19.
Summary Seedlings ofLepidium sativum L. contain 4 peroxidase isoenzymes. Their de-novo-synthesis is significantly depressed in the presence of 3·10–3 moles/l silybin, silydianin and silychristin in the incubation medium respectively.  相似文献   

20.
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