Effect of pentobarbital on the synaptosomal activity of acetylcholinesterase in Mongolian gerbils

The influence of Na pentobarbital anesthesia on the activity of specific and nonspecific cholinesterase was studied in the synaptosomal fraction of Mongolian gerbils' brains. These studies have shown that this barbiturate inhibits the specific activity of acetylcholinesterase only.     

Effect of orchidectomy and estradiol on acetylcholinesterase activity in rat brain areas and adenohypophysis

Orchidectomy plus estradiol administration decreased acetylcholinesterase activity in the rat cerebral cortex and mesencephalon, while in the amygdala it was increased. In the adenohypophysis, orchidectomy increased enzyme activity, but subsequent estradiol treatment decreased it. The hypothalamus did not respond to either manipulation.     

Effect of orchidectomy and estradiol on acetylcholinesterase activity in rat brain areas and adenohypophysis

Summary Orchidectomy plus estradiol administration decreased acetylcholinesterase activity in the rat cerebral cortex and mesencephalon, while in the amygdala it was increased. In the adenohypophysis, orchidectomy increased enzyme activity, but subsequent estradiol treatment decreased it. The hypothalamus did not respond to either manipulation.     

Effects of later isolation housing on both scent marking behavior and brain cholinergic activites in Mongolian gerbils

Summary Significant difference in the frequency of marking was found between aggregated and isolated gerbils. As compared with the aggregated gerbils, isolated gerbils showed high acetylcholinesterase activity in the hippocampus and high choline acetyltransferase activity in the hypothalamus.The authors are indebted to Dr Masaru Sorimachi of the Department of Physiology. Ehime University, for pertinent advices and professional assistance in radiochemical assay.     

5-hydroxytryptamine-sensitive adenylate cyclase activity in brain synaptosomal membrane preparations]

A serotonine-sensitive adenylate cyclase system has been observed in horse brain membrane preparations. In crude mitochondrial fraction two types of activation sites were characterized, the Ka being = 2 nM and 1 micrometer. In purified synaptosomal membranes, a single adenylate cyclase activation was observed corresponding to the highest apparent affinity (KD = 2nM). This activation site might be related to the high affinity binding site (KD = 2NM) were previously described in the same membrane preparations.     

Pentagastrin induction of acetylcholinesterase activity in cerebral cortex of rats

Summary A single injection of pentagastrin (500 g kg^–1) produced an immediate (within 15 min) and pronounced increment (about 50%) in the activity of acetylcholinesterase (AChE) in the cerebral but not in the cerebellar region of the brain. Pretreatment of rats with either actinomycin-D or cycloheximide did not fully abolish the pentagastrin-mediated stimulation of cerebral AChE activity.Acknowledgments. A.M. Nakhla is recipient of a postdoctoral research fellowship from Danida, Ministry of Foreign Affairs, Denmark. The project was in part supported by grants to A.P.N.M. from The Laegevidenskabelige Forskningsråd and Danida, Denmark.     

Effect of antibrain synaptosomal fraction serum and complement on evoked potentials and impedance

Résumé L'introduction du «complément» (sérum de cobaye) dans le corps genouillé latéral du chat, produit une diminution des potentiels évoqués photiques et de l'impédance cérébrale. Ces effets sont prévenus par l'application locale d'un anti-serum réagissant spécifiquement avec les synaptosomes cérébraux.     

Eyestalks control of diurnal rhythm of acetylcholinesterase activity in the crabOziotelphusa senex senex

Summary The crab (Oziotelphusa) displays a diurnal rhythm of acetylcholinesterase activity, with maximal activity around midnight, alternating with minimal activity at noon. Bilateral eyestalk ablation eliminates the diurnal rhythm of acetylcholinesterase activity.Acknowledgments. We wish to express our gratitude to CSIR, New Delhi for providing financial support to PSR. Reprint requests should be addressed to Prof. R. Ramamurthi.     

Localization of acetylcholinesterase activity in myotendinous and myomyous junctions of the striated skeletal muscles of the rat

Zusammenfassung Mit licht- und elektronenmikroskopischen Methoden wird demonstriert, dass die quergestreiften Muskelfasern sich ohne kollagenes Bindegewebe an andere Muskelfasern anschliessen können. An den gegenüber liegenden Sarcoplasmamembranen konnte Azetylcholinesterase nachgewiesen werden.     

Quantitative determination of acetylcholinesterase activity in individual megakaryocytes at various stages of maturation

Zusammenfassung Die Aktivität der Azetylcholinesterase von einzelnen Megakaryozyten verschiedener Reifegrade wurde mit Hilfe des Cartesischen Tauchers bestimmt. Die Megakaryozyten zeigen auf dem Megakaryoblasten- und Promegakaryozytenstadium grosse Unterschiede der Azetylcholinesteraseaktivität. In der letzten Phase der Reifung, wenn die Zellen einen Durchmesser von 45 µ erreichen, wird das Ferment am stärksten wirksam.     

Changes in brain acetylcholinesterase activity of young rats after chronic treatment with tremorine

Résumé La trémorine a été administrée chez les rats quotidiennement pendant 7 jours à des doses de 7.5, 22.5 ou 30 mg/kg. Les témoins ont montré des mouvements convulsifs proportionnels à la dose de trémorine. Quatre jours après l'arrêt du traitement, l'activité acétylcholinestérasique du cortex cérébral était augmentée. Il est proposé que ce change de l'activité acétylcholinestérasique reflète une utilisation accrue de l'acétylcholine corticale.

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Acknowledgement: This investigation was supported by a U.S. Public Health Service Grant No. NS 09199 and a Research Scientist Development Award No. K02 MH-42479 from the National Institute of Mental Health, National Institutes of Health.

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The author gratefully acknowledges the technical assistance ofSandra Roland.     

Manganese prolongation of pentobarbital hypnosis in the male rat

Summary Following manganese treatment, pentobarbital hypnosis was prolonged in male rats. The maximal effect occurred from 1 to 3 days following manganese treatment and the threshold dose was found to be 3 mg Mn⁺⁺/kg (i.p.).Acknowledgments. This work was supported by NIEHS Research Grant ES-02425. These data were submitted as part of a Ph.D. thesis to Purdue University, West Lafayette, Indiana, by M.J. Deimling.     

Concerning the anchoring of acetylcholinesterase in biomembranes

Highly purified acetylcholinesterases from various sources do not contain hydroxyproline and hydroxylysine, indicating the absence of a collagenlike 'tail'. The enzymes examined are therefore bound to the membrane in a different way compared with acetylcholinesterase isolated from electric organ.     

Concerning the anchoring of acetylcholinesterase in biomembranes

Summary Highly purified acetylcholinesterases from various sources do not contain hydroxyproline and hydroxylysine, indicating the absence of a collagenlike tail. The enzymes examined are therefore bound to the membrane in a different way compared with acetylcholinesterase isolated from electric organ.     

The effect of pentobarbital on brain 5-HT metabolism in mice

Zusammenfassung Bei Mäusen erhöhte Pentobarbital den Serotoningehalt des Gehirns, ein Effekt, der sich durch eine Verminderung der Umsatzgeschwindigkeit bei unveränderter Synthese des Serotonins erklären lässt.

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Acknowledgment: We are indebted to the Deutsche Abbott GmbH for a generous gift of pargyline.