Inhibition of testicular androgenesis by urinary gonadotropin-inhibiting substances in rats

The effect of urinary gonadotropin-inhibiting substances (GIS) on the androgen synthesis in rat testes was studied in vitro and in vivo. GIS, which was added to the incubation medium containing tesased testicular tissues and injected into rats for 2 days, showed a suppressive effect on the formation of androstenedione from pregnenolone in the testis.     

Inhibition of testicular androgenesis by urinary gonadotropin-inhibiting substances in rats

Summary The effect of urinary gonadotropin-inhibiting substances (GIS) on the androgen synthesis in rat testes was studied in vitro and in vivo. GIS, which was added to the incubation medium containing teased testicular tissues and injected into rats for 2 days, showed a suppressive effect on the formation of androstenedione from pregnenolone in the testis.Supported by a Scientific Research Grant from the Ministry of Education of Japan.     

Autoantibody formation against spleen in rats ‘chemically splenectomized’ by ethyl palmitate

Summary The follow-up experiments with rats revealed auto-antibodies against spleens damaged by an i.v. ethyl palmitate injection. The antibodies could be shown in some animals only.     

Separation of two strains of rats with inbred dissimilar sensitivity to doca-salt hypertension

Résumé La réponse au régime Doca-sel (D. S.) a été utilisée comme critère de sélection pour séparer, par croisement consanguin, deux colonies de rats manifestant une susceptibilité bien différente à l'hypertension artérielle. Les résultats obtenus dans la 6ème génération de nos colonies normotensive et hypertensive font l'objet de ce raport. Le rôle des facteurs héréditaires dans la susceptibilité ou la résistance à l'hypertension du type D. S. est démontrée.     

Selective depletion of spinal noradrenaline inhibits post-decapitation convulsions in rats

Summary Local administration of 6-hydroxydopamine in the subarachnoidal space of the spinal cord in rats resulted in a selective long-lasting depletion of spinal noradrenaline, but not of dopamine, and prevented the occurrence of postdecapitation convulsions.     

Effects of theophylline on chemically induced liver tumorogenesis and on bladder membranes in rats]

The addition of theophylline to the diet of rats given the carcinogen 4-dimethylaminoazobenzene did not significantly impair the development of hepatomas. In contrast, the feeding of theophylline has been associated to some histopathological changes in bladder membrane leading to the occurrence of malignant papillomas.     

The increase of thiobarbituric acid reacting substances in rats with experimental chronic hypoxia

Summary Feeding under conditions of reduced oxygen supply prompted an increase in serum, arterial and brain tissue levels of thiobarbituric acid (TBA)-reacting substances. These observations indicated the possibility that hypoxia might be one of the factors predisposing to the accumulation of lipid peroxide.     

Production of temperature signals in the peripherally denervated spinal cord of the dog

Summary Selective warming of the spinal cord with ventral and dorsal roots cut can generate panting in the conscious dog.     

Production of underweight embryos in rats treated with barbiturates during pregnancy

Summary The effect of administering barbital sodium, phenobarbitone or butobartitone during pregnancy was investigated in rats. The study shows that these bartiturates affect the litter-size and retard the foetal growth markedly. The embryos produced are significantly undersized.Acknowledgments. The authors wish to express their gratitude to Prof. M. R. Rajasekar Setty for the encouragement received and CSIR, India, for the award of a Research Fellowship to A. V. Champakamalini.     

Selective activation of noradrenergic neurons in the brainstem and spinal cord of young spontaneously hypertensive rats

Summary In young spontaneously hypertensive rats (SHR), dopamine -hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT) activities were examined in the brainstem nuclei. Activation of noradrenergic neurons in the locus coeruleus, A2 and spinal intermediolateral cell areas, resulting in enhanced sympathetic nervous activity in the periphery, initiates hypertension. Adrenergic neurons, unchanged in these and A1 cell areas of young SHR, are not involved in the development of hypertension in SHR.     

Prophylaxis of chemically induced papillomas and carcinomas of mouse skin by vitamin A-Acid

Zusammenfassung Oral verabreichte Vitamin-A-Säure besitzt bei Mäusen eine prophylaktische Wirkung auf die Entstehung von hauptpapillomen und Hautkarzinomen. die mittels lokaler Applikation von Dimethylbenzanthracen und Krotonöl erzeugt wurden. Vitamin-A-Säure verzögert das Auftreten, verlangsamt das Wachstum und führt zur Rückbildung von Papillomen. Ferner wird die Induktion von Karzinomen gehemmt. Diese treten bei prophylaktischer Verabreichung von Vitamin-A-Säure verzögert und in deutlich verringerter Anzahl auf. Der Wirkungsmechanismus wird diskutiert.