Thein vitro effect of various enzymes upon the mouse ascites tumor of ehrlich

Zusammenfassung Die Virulenz von Ehrlich-Ascitestumorzellen wurde durch Inkubation mit fünf Enzymenin vitro stark herabgesetzt. Zwölf andere Enzyme hatten keine Wirkung. Die morphologischen Kriterien für Zellschädigung werden erörtert.

---

---

This work was supported in part by a grant from the American Cancer Society (Mass. Division) and in part by grants (C-3538 and CY-4018) from the U.S. Public Health Service, National Cancer Institute.     

Diminution of 5-hydroxytryptamine in thrombocytesin vitro by chlorpromazine and related compounds

Riassunto Cloropromazina, imipramina, cloroprotixene e amitriptilinain vitro diminiscono la 5-idrossitriptamina (5HT) endogena nei trombociti di coniglio e, per quanto si è visto, anche in quelli umani. Nel plasma di coniglio pretrattato con isocarbossazide, inibitore della mono-amino-ossidasi, si osserva un corrispondente aumento di 5HT. Cocaina, -metil-dopa e triptamina hanno un effetto meno pronunciato sulla 5HT delle piastrine.

---

---

Guest worker from the Istituto di Patologia sp. Medica dell'Università di Bologna (Italy).     

In vitro inhibition of catalase by ovomucoid

Riassunto L'ovomucoide acquista spiccata attività anticatalasica dopo ebollizione. L'ovomucoide attivo dopo liofilizzazione o precipitazione alcoolica diviene inattivo; l'attività viene ripristinata con nuova ebollizione. L'ovomucoide attivo anche dopo dialisi perde l'attività che viene riacquistata con l'aggiunta di sali e successiva ebollizione. L'attività anticatalasica è dovuta ad una nuova configurazione instabile dell'ovomucoide.     

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.

---

---

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

Testosterone metabolism by mouse placenta in vitro

Zusammenfassung 4-C¹⁴-Testosteron wurde durch Mäuseplazenta in vitro zu Steroiden umgesetzt: 3-Hydroxy-5-androstan-3, 17-dion, 3-Hydroxy-5-androstan-3, 17-dion, 4-Androsten-3, 17-dion und 5-Androstan-3, 17-dion. Eine Umsetzung von Testosteron zu Östrogenen wurde nicht nachgewiesen.     

In vitro Polio virus inhibition by two guanidino-pyrimidines

Riassunto La 2-guanidino-pirimidina solfato e la 4-guanidino-2,6-dimetilpirimidina solfato inibisconoin vitro la moltiplicazione del poliovirus e del Coxsackie B₃ ma non quella del virus vaccinico e dell'adenovirus 5. L'analogia di comportamento con la guanidina è documentata oltre che da ciò, dalla esistenza di una resistenza e di una dipendenza crociata. Si dimostra cioè che non tutte le sostituzioni nella molecola della guanidina comportano una perdita dell'attività antivirale, come ritenuto in precedenza.     

Steroid metabolism by mouse preimplantation embryos in vitro

Summary Mouse preimplantation embryos were incubated with radioactive pregnenolone, progesterone or dehydroepiandrosterone for various periods of time. These substrates were not converted to metabolites even after incubation of 120 h. We suggest that preimplantation mouse embryo does not possess enzyme activities for steroid metabolism.Acknowledgments. The authors would like to thank Prof. L. Saxén for giving the animals and the facilities of his tissue culture laboratory.     

The inhibition of amphibian ovulation in vitro by cytochalasin B

Zusammenfassung Cytochalasin B (5 g/ml) verhindert in vitro vollständig die inRana pipiens undHyla regilla durch Gonadotropinbehandlung stimulierte Ovulation, während die Meiose weiter abläuft. Diese Resultate werden mit früheren Beobachtungen einer ähnlichen Empfindlichkeit der Follikelzellenbewegung bei Seesternen verglichen. Ein für Echinodermen und niedere Wirbeltiere gemeinsamer Follikelmechanismus für die Austreibung des Ovarialeies aus dem Ovar wird vorgeschlagen.

---

---

Supported by funds provided for biological and medical research by State of Washington Initiative Measure No. 171. The competent assistance ofP. Pendergrass andM. Vandenbark is gratefully acknowledged.     

In vitro inhibition of anaerobic glycolysis by phenothiazine ataractic drugs

Zusammenfassung Im Gegensatz zu Feststellungen anderer Forscher hemmten Chlorpromazin und zwei strukturell verwandte ataraktisch wirkende Phenothiazinderivate die anaerobe Glykolyse von homogenisiertem Rattenhirn. Der Nachweis dieser Hemmung bedarf einer längeren Inkubation, was auf die Mitwirkung eines zeitbedingten Vorgangs, wie metabolische Umwandlung der Phenothiazine in Hemmstoffe, deutet.     

Steroid metabolism by mouse preimplantation embryos in vitro.

Mouse preimplantation embryos were incubated with radioactive pregnenolone, progesterone or dehydroepiandrosterone for various periods of time. These substrates were not converted to metabolites even after incubation of 120 h. We suggest that preimplantation mouse embryo does not possess enzyme activities for steroid metabolism.     

Progesterone formation and metabolism by rabbit placenta in vitro

4-¹⁴C-Progesterone and 4-¹⁴C-pregnenolone are metabolized in vitro by rabbit placenta, at day 15 and 28 of gestation, exclusively to compounds reduced in ring A (5) and at carbon 3 and 20.     

Inhibition of noradrenaline release from sympathetic nerves by pentobarbital

Summary Pentobarbital concentrations of 10–100 M selectively inhibited the noradrenaline release evoked by activation of the nicotinic receptors on the terminals sympathetic nerves of the rabbit heart. Higher concentrations also decreased the noradrenaline release induced by KCl or by electrical stimulation of the nerve axons.This paper is dedicated to Professor Dr. G. Malorny on the occasion of his 65th birthday.Acknowledgment: We thank Mrs G. Thielecke for technical assistance.     

Inhibition of noradrenaline release from sympathetic nerves by pentobarbital

Pentobarbital concentrations of 10--100 micrometer selectively inhibited the noradrenaline release evoked by activation of the nicotinic receptors on the terminals sympathetic nerves of the rabbit heart. Higher concentrations also decreased the noradrenaline release induced by KCl or by electrical stimulation of the nerve axons.