Depletion of cerebral monoamines byp-chlorophenylalanine in the cat

Zusammenfassung p-Chlorphenylalanin, ein Inhibitor der Serotoninbiosynthese, senkte bei Katzen den Serotoningehalt des Gehirns nicht selektiv. Es wurde gleichzeitig eine signifikante und langanhaltende Erniedrigung des Noradrenalin- und Dopamingehalts gefunden.     

Changes in cerebral blood supply caused by changes in the pressure drop along arteries to the brain of the cat

Zusammenfassung Bei der Katze kann der Druckabfall in den extra- und intrakraniellen Anteilen der Hirnarterien unter gewissen Bedingungen genügend gross werden, um die Hirndurchblutung in eindeutiger Weise zu beeinflussen. Schwankungen des Druckgradienten in den Arterien werden durch die arterielle Vasomotorik und Veränderungen der Durchströmung derjenigen Gewebe bedingt, die von den Aa. carotidae externae versorgt werden.     

Nonsympathetic dilator innervation of cat cerebral arteries.

The results presented provide strong support for the presence of vasodilator innervation in the cat cerebral arteries. The dilator innervation is neither adrenergic nor cholinergic and does not originate in the superior cervical ganglia. The nature of the vasodilator transmitter is unidentified. Such innervation, however, may be involved in the regulation of cerebral blood flow, especially in view of the capability of some cat cerebral vessels to develop intrinsic muscle tone.     

Localization of monoamines in the lower brain stem

Zusammenfassung Histochemische und pharmakologische Experimente sprechen stark dafür, dass Dopamin, Noradrenalin und 5-Hydroxitryptamin im Hirnstamm der Ratte in drei Typen von Nervenzellen und Endsynapsen gespeichert werden.     

Decrease of litter size and fetal monoamines by 6-hydroxydopamine in mice

Zusammenfassung 6-Hydroxydopamin, am Muttertier appliziert, geht in den Foetus und reduziert die Wurfgrösse ohne den Östruszyklus zu stören.

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Acknowledgments. Supported in part by the National Research Council for Natural and Medical Sciences, Finland, by Sigrid Jusélius Foundation and by Alatonen Foundation.     

Hyperthermic effect of disodium edetate injected into the lateral cerebral ventricle of the unanesthetized cat

Résumé La chélation des ions de calcium par l'EDTA Na₂ injecté dans le ventricule cérébral des chats non anesthésiés a produit une réaction hyperthermique caractérisée par une installation rapide et une durée brève. Cette réaction peut être bloquée par l'anesthésie au pentobarbital, mais non pas par les antipyrétiques, le N-acétyl-paraaminophénol ou le salicylate de sodium. Les résultats indiquent une action plus tardive dans la chaîne des événements que celle des pyrogènes.     

Prostaglandin E1-induced fever in rabbits pretreated with p-chlorophenylalanine

Summary The prostaglandin E₁-induced fever was neither potentiated nor attenuated at all levels of the ambient temperatures (2, 22 and 32°C) studied after pretreatment of the conscious rabbits with p-chlorophenylalanine, when compared to the untreated control.This work was supported by grants from National Science Council of Republic of China and John B. Pierce Foundation (New Haven, USA). The author is grateful to Drs J. D. Hardy, J. T. Stitt and C. Y. Chai for their advice.     

Prostaglandin E1-induced fever in rabbits pretreated with p-chlorophenylalanine.

The prostaglandin E1-induced fever was neither potentiated nor attenuated at all levels of the ambient temperatures (2, 22 and 32 degrees C) studied after pretreatment of the conscious rabbits with p-chlorophenylalanine, when compared to the untreated control.     

Oculomotor reflex evoked by vibrassae stimulation in the cat]

The oculomotor effects of vibrissae stimulation have been studied in the "encéphale isolé" non-anaesthetized Cat. Intracellular recording of lateral rectus motoneurones showed an excitatory projection via the ipsilateral infraorbital nerve to these motoneurones. The afferent fibers are type A alpha, recuited with a low threshold (0.2-0.5 mA) and convey information about vibrissae displacement.     

Changes in the distensibility of the cat aortic arch induced by noradrenaline

Summary In the isolated preparation of the aortic arch of the cat, noradrenaline (NA) reduced at low pre-loads, and increased at high pre-loads, the arterial wall distensibility. For each dose of NA, the changes were directly related to the pressure level in the system.     

Inhibition of reserpine-induced PGO waves in the cat by ergot derivatives

Summary The number of reserpine-induced PGO waves in the cat is decreased by administration of ergot derivatives. The inhibition is dose-dependent and the various ergot derivatives show differing potencies. The action of the ergot derivatives may result from stimulation of central serotonin receptors. In addition, possible involvement of dopaminergic systems is discussed.     

Periodic depression by N-methyl-N-nitrosourea of electrocortical activity in the cat brain

Zusammenfassung An Katzen wurden die Auswirkungen von N-Methyl-N-Nitrosamin auf das EEG untersucht. Die intracarotidale Injektion von 60 mg dieser Substanz bewirkt einseitige zyklische Depressionen des EEGs, die über mehrere Stunden anhalten können.