Electron microscope observation of "thyroidectomy cells" in the hypophyseal ventral lobe of a Chondrichthyan fish, the small spotted dogfish, Scyllium canicula Cuv.]

In the adenohypophysis of very young spotted dogfish, only one kind of granulated cells show strcutural changes following thyroidectomy: the small granule cells of the ventral lobe (granule diameter about 110 nm). These cells are similar to the thyrotrophs of other Vertebrates, and well distinct from the supposed gonadotrophs found in the same lobe.     

Sperm activation inBalanus balanoides (Crustacea: Cirripedia)

Summary Ammonium ions alone will activate both vesicula and inseminated spermatozoa ofBalanus balanoides. Maximum activity, however, occurs when inseminated spermatozoa are treated with the blood and oviducal gland fluid ofB. balanoides.Acknowledgments. I should like to thank Mr K. White for the ammonia determinations and Prof. D. J. Crisp and Dr P. A. Gabbott for useful discussions.     

Nicotinamide administration alters the activities of hepatic microsomal mixed function oxidases

Summary Systemic action of nicotinamide significantly alters the activities of hepatic drug metabolizing enzymes. Male rats injected with nicotinamide have reduced levels of cytochrome P450, demethylases and aniline hydroxylase. The changes appear to be sex-dependent since in the case of female rats activities of p-nitroanisole-o-demethylase and aniline hydroxylase are enhanced whereas cytochrome P450 content remains unaltered.Authors gratefully acknowledge the encouragement given by Professor A.S. Paintal during the course of this investigation. One of us (J.K.B.) is grateful to the Council of Scientific and Industrial Research, New Delhi, for the award of a research fellowship.     

Pressor and oxitocic-like effects of angiotensin affected by aldosterone pretreatment in guinea-pigs

Résumé Les auteurs examinent l'augmentation de l'action de l'angiotensine sur la pression carotidienne et sur la contraction utérine chez des animaux traités avec de l'aldostérone. Ils pensent aussi que le traitement conditionne le développement du phénomène taquiphylactique de l'angiotensine.     

A quantitative difference in the immune response to sheep red cells between rat strains

Résumé Des rats appartenant à plusieurs souches ont été immunisés par injection i.p. de 2×10⁸ globules rouges de mouton. La mesure du titre des haemolysines réalisée 6 jours plus tard montre des différences quantitatives selon les souches. Une réponse importante n'a pu être décelée que pour 3 d'entre elles (August, OFA et Wistar R).     

A new method for measuring guanidine in uremia

Riassunto Si descrive un metodo per la determinazione della guanidine nei liquidi biologici e si rileva che essa aumenta nel siero uremico fino a 30 volte la norma (valore medio normale: 1.41±0.49 g/100 ml) e che nei cani uremici la concentrazione muscolare è di quasi 3 volte superiore a quella plasmatica. La eliminazione urinaria non è diversa fra normali ed uremici: 382±221 e 459±229 g/24 h, rispettivamente.

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Aknowledgments. This investigation was supported by Public Health Service, Research Contract No. PH-43-68-1466.     

Strain difference in sex ratio response of mice to lactate dehydrogenase virus infection

Zusammenfassung Durch Infektion mit LDH-Virus wird bei Mäusen, deren Nachkommen normalerweise ein Geschlechtsverhältnis <1 aufweisen, ein solches von 1 erreicht. Da sich die Infektion der Eltern beider Stämme nicht in einer unterschiedlichen Zunahme der Serum-LDH, wohl aber in einer solchen der Spermien-LDH auswirkt, wird angenommen, dass die LDH-Aktivität der Spermien sich in einer zwar noch unbekannten Weise auf das Geschlechtsverhältnis der Nachkommen auswirkt.

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Supported by a grant from the Maryland Division of the American Cancer Society.