Binding of 5-hydroxytryptamine and noradrenaline by rat lung

Résumé Après injection i.v. de 5-hydroxatryptamine-C¹⁴ et de noradrénaline-H³ à des rats, on a préparé et centrifugé des homogénates de leurs poumons dans un gradient linéaire de sucrose. Après sacrifice immédiat ces deux amines sont retrouvées dans une grande fraction de particules pulmonaires sédimentant dans 1M de sucrose. Après 30 min les poumons des rat offrent un pic additionel de noradrénaline-H³ correspondant à une densité de sucrose de 0.4 à 0.5.

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This work was supported in part by Grant No. 13315 from the U.S. Public Health Service and by Grant No. 435 from the Connecticut Heart Association. Assistance provided by Ayerst Laboratories and Astra Laboratories is also gratefully acknowledged.     

Distribution of radioactivity after administration of3H-5-hydroxytryptamine by three different routes to the musselMytilus edulis

Summary Intracardiac injection gives proportionately higher and earlier peak concentration in tissues that specifically accumulates it, i.m. injection gives slower but longer lasting accumulations, and topical application to a ganglia essentially localizes the drug in that structure.We wish to thank Drs Hiripi and Nemcsok for the demonstration of the intracardiac technique. We also wish to thank Drs Haley and Ledeen for the use of the scintillation counter.     

Post mortem increase of 5-hydroxytryptamine in rat brain after 5-hydroxytryptophan administration

Zusammenfassung Ratten mit und ohne Iproniazid-Vorbehandlung erhielten 30 min vor Dekapitation 5-Hydroxytryptophan (5HTP) i. p. Das intakte Hirn wurde bis zu 4 h bei 37° C, Zimmertemperatur und in 0·1n HCl aufbewahrt. In allen Fällen ergab sich eine starke postmortale 5-Hydroxytryptamin (5HT)-Vermehrung im Gehirn.Bei unbehandelten Kontrolltieren zeigte sich postmortal ein leichter 5HT-Abfall im Gehirn, der durch Iproniazid-Vorbehandlung aufgehoben wurde.     

A histamine-dependent increase of 5-hydroxytryptamine in the rat brain in vivo

Résumé Pendant l'excitation du systeme nerveux central du rat, on constate une augmentation de l'histamine et de la sérotonine cérébrales. L'augmentation de la sérotonine dépend de celle de l'histamine.     

Uptake ofl-glutamate andl-aspartate in neurones and glial cells of cultured human and rat spinal cord

Summary Autoradiographic investigations on the uptake ofl-glutamate andl-aspartate have shown that the amino acids were taken up by neurones as well as by glial cells of cultured human and rat spinal cord. The activity of glutamate and aspartate varied considerably between individual neurones, whereas glial cells showed a more even distribution of the labelled amino acids. Our results suggest that both neurones and glial cells are involved in the uptake of amino acid transmitters.     

Comparison of diurnal and nocturnal rates of 5-hydroxytryptamine turnover in the rat mediobasal hypothalamus

Rates of 5-hydroxytryptamine (5-HT) turnover in the mediobasal hypothalamus of male rats were estimated using pharmacological methods during the daytime and at night. Concentrations of 5-HT in this hypothalamic area were higher nocturnally than diurnally; this was apparently due to increased 5-HT synthesis and decreased 5-HT catabolism at night.     

Comparison of diurnal and nocturnal rates of 5-hydroxytryptamine turnover in the rat mediobasal hypothalamus

Summary Rates of 5-hydroxytryptamine (5-HT) turnover in the mediobasal hypothalamus of male rats were estimated using pharmacological methods during the daytime and at night. Concentrations of 5-HT in this hypothalamic area were higher nocturnally than diurnally; this was apparently due to increased 5-HT synthesis and decreased 5-HT catabolism at night.Supported by NIH grant RR07187 (TSK) and NIH grant HD10202 (Neuroendocrine Core).     

Uptake of L-glutamate and L-aspartate in neurones and glial cells of cultured human and rat spinal cord.

Autoradiographic investigations on the uptake of L-glutamate and L-aspartate have shown that the amino acids were taken up by neurones as well as by glial cells of cultured human and rat spinal cord. The activity of glutamate and aspartate varied considerably between individual neurones, whereas glial cells showed a more even distribution of the labelled amino acids. Our results suggest that both neurones and glial cells are involved in the uptake of amino acid transmitters.     

Observations on the metabolism of endogenous 5-hydroxytryptamine (enteramine) in the rat

Zusammenfassung Der Rattenurin enthält 1,34µg 5-Hydroxyindolyl-essigsäure je Kubikzentimeter (=81,4µg/kg/24 h). Daraus ist zu berechnen, dass in der Ratte täglich 216–236µg/kg 5-Hydroxytryptamin metabolisiert werden. Dies bedeutet, dass das Blutplättchen-5-HT alle 3–4 h und das Gesamt-5-HT des Organismus alle 12–14 h erneuert werden wird.Die erhaltenen quantitativen Daten sind hauptsächlich im Hinblick auf die fragliche Bildungsstelle des 5-HT und die biologische Bedeutung der Substanz selber wichtig.     

5-hydroxytryptamine content of glioma

Résumé La teneur en 5-HT de tumeurs intra-crâniennes humaines, déterminée par une méthode biologique, est en général plus faible que celle du cortex cérébral adjacent. Cette observation n'est pas en faveur de l'hypothése que la 5-HT est localisée dans les cellules névroglies.     

Reserpine and human platelet 5-hydroxytryptamine

Zusammenfassung Nach einmaliger intramuskulärer Injektion von 1 mg Reserpin sinkt beim Menschen der 5-Oxytryptamingehalt der Blutplättchen zwei Tage lang ab, um bis zum neunten Tag auf unbestimmbarem Wert zu verharren. Während dieser Zeit ist die 5-OT-Aufnahmefähigkeit der Plättchen vermindert. Der Oxytryptamingehalt der Plättchen erreicht seinen Ausgangswert erst ungefähr 3 Wochen nach der Reserpingabe.Die Ansicht, dass die Plättchen freies 5-Oxytryptamin aus dem Kreislauf aufnehmen, wäre mit diesem Ergebnis zu vereinbaren. Die Dauer des Effektes könnte bedeuten, dass Reserpin entweder auf Plättchenvorstadien im Knochenmark wirkt oder aber dass die Lebensdauer der Plättchen in Wirklichkeit länger ist, als neuerdings angenommen wird.     

Hypertension mediated by the activation of the rat brain 5-hydroxytryptamine receptor sites

Summary 5-Hydroxytryptamine (5-HT) administered intraventricularly (i.vent.) in rats produced hypertension without considerable changes in heart rate. After transsection of the spinal cord or i.vent. administration of methysergide, 5-HT failed to produce the pressor effect. Thus, the hypertension results from the activation of 5-HT receptor sites of the rat brain.This work was supported by Union of Scientific Medical Institutions of Serbia (Grant No. 85).     

Occurrence of 5-hydroxytryptamine in chick retina

Summary 5-Hydroxytryptamine (5-HT) was found in chick retina. 5-HT level in chick retina was increased by the administration of pargyline and decreased by reserpine, but remained unchanged with tryptophan.