Uptake of C14-ethionine by mouse foetuses

Zusammenfassung Trächtige Mäuse wurden zwei Tage vor dem erwarteten Werfen mit dem Antimetabolit des Methionins¹⁴C-DL-Aethionin intravenös behandelt. Aufnahme und Einbau des Antimetabolits wurden gleichzeitig autoradiographisch und chemisch untersucht. Die Plazentaschranke ist für Aethionin durchlässig; die Radioaktivität fand sich in den Foeten angehäuft, dabei war aber nur ein ganz geringer Teil des Aethionins in den Eiweisskörper derselben eingebaut. Der Einbau des Aethionins in den Organen (Leber und Pankreas) der Mutter war ebenfalls äusserst gering.Aus den Ergebnissen wird der Mechanismus der toxischen Wirkung des Aethionins erklärt.

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This work was supported by grants from the Swedish Medical Research Council.     

Dominant lethal mutations induced by14C in mice

Summary The mutagenic potential of 1.0 Ci¹⁴C was evaluated in Swiss albino male mice by the dominant lethal assay. A significant increase in post-implantation loss was seen, the maximum being in the 3rd week after treatment.Authors express their thanks to University Grants Commission, New Delhi, for financial assistance.     

Uptake of glucose-C14 and fructose-C14 by buffalo spermatozoa in extenders during cold storage

Summary Buffalo spermatozoa exhibit insignificant uptake of glucose-C¹⁴ and fructose-C¹⁴ when semen samples were preserved in cold for 96 h in 2 extenders. Incorporation of C¹⁴ in spermatozoa, TCA precipitable proteins and soluble sugar phosphates was either equal or less in semen samples preserved in cold. CAW appeared to be a better extender than SKMEY as revealed by sugar uptake in cold.Acknowledgment. We are indebted to Dr D. Sundaresan, Director, for his kind encouragement in this study.     

Uptake of glusose-C14 and fructose-C14 by buffalo spermatozoa in extenders during cold storage

Buffalo spermatozoa exhibit insignificant uptake of glucose-C14 and fructose-C14 when semen samples were preserved in cold for 96 h in 2 extenders. Incorporation of C14 in spermatozoa, TCA precipitable proteins and soluble sugar phosphates was either equal or less in semen samples preserved in cold. CAW appeared to be a better extender than SKMEY as revealed by sugar uptake in cold.     

Uptake of tolbutamide by islets of Langerhans and other tissues

Summary 3-H-tolbutamide was distributed in a volume exceeding the space occupied by 14-C-sucrose in islets as well as in liver, kidney, muscle, and fat. In contrast to previous reports, the findings suggest that tolbutamide is not restricted to the extracellular space of islets.     

Synthesis of ecdyson-14C and ecdysterone-14C from cholesterol-14C in cockroaches (Periplaneta americana) without molting glands

Summary The synthesis of molting hormone of cockroaches of which the prothoracic glands had previously been extirpated was investigated after injection of cholesterol-¹⁴C. It could be proved by means of radio thin-layer chromatography of extracts that ecdysterone and in small amounts ecdysone, are synthesized in Periplaneta americana larvae without prothoracic glands. The results demonstrate that other tissues are also able to perform the molting hormone besides the molting gland itself.Supported by the Sächsische Akademie der Wissenschaften zu Leipzig.     

Uptake of tolbutamide by islets of Langerhans and other tissues.

3-H-tolbutamide was distributed in a volume exceeding the space occupied by 14-C-sucrose in islets as well as in liver, kidney, muscle, and fat. In contrast to previous reports, the findings suggest that tolbutamide is not restricted to the extracellular space of islets.     

Distribution of14C after topical application of14C-labeled 1,3-bis-(2-chloroethyl)-1-nitrosourea (BCNU) in mice

Summary Following topical application of¹⁴C-labeled 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU, carmustine) to the skin of mice radioactivity was found in all viscera and tissues examined. Exclusive of the gut, highest values were recorded for the liver, kidney and lung.Supported by Public Health Service, grant CA 14825, from the National Cancer Institute, National Institutes of Health, Department of Health, Education and Welfare.     

Degradation of haemoglobin-14C and urinary excretion of bilirubin-14C by the normothermic perfused isolated dog kidney

Résumé L'hémoglobine libre du sang, filtrée par les glomérules rénaux et partiellement absorbée par les tubules, est métabolisée par le tissu renal. A l'aide de l'hémoglobine marquée en¹⁴C, formée à partir de la glycine-2-¹⁴C et de la glycine-1-¹⁴C nos résultats prouvent que chez le chien mâle les reins métabolisent l'hémoglobine en bilirubine conjugée et excrètent cette dernière dans les urines.

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Our thanks are due to the Fonds voor wetenschappelijk geneeskundig onderzoek of Belgium for the financial support.     

Urinary excretion of C14-histamine and metabolites in cats after C14-histamine given intravenously,and into the cerebral ventricles

Zusammenfassung In narkotisierte Katzen wurde C¹⁴-Histamin entweder durch Hirnventrikel perfundiert oder intravenös injiziert. Seine Ausscheidung und Metabolite in Urin wurde gleichzeitig bestimmt: Ca. 2% des durch die Hirnventrikel perfundierten C¹⁴-Histamins wurde im Blutstrom resorbiert.     

Gastric excretion of C14-nicotine

Zusammenfassung Der Übertritt von C¹⁴-Nicotin aus der Magenschleimhaut von Mäusen, Ratten und Katzen in den Mageninhalt wurde autoradiographisch und mit Radioaktivitätsmessungen untersucht. Perfusionsversuche des Rattenmagens in situ ergaben eine pH-abhängige Nikotinausscheidung. Chromatographisch wurde die ausgeschiedene Radioaktivität teils im Nikotin selber, teils im Abbauprodukt Cotinin nachgewiesen.

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This investigation was supported by grants from Svenska Tobaks AB and the American Medical Association.     

Serum and liver radioactivity levels in mice after intraperitoneal and subcutaneous injection of [14C]orotic acid

Summary [¹⁴C]Orotic acid was rapidly distributed in blood after, both i.p. and s.c. injection but was not completely absorbed from the peritoneal cavity until 20 min after injection. S.c. injection should be an acceptable alternative to i.p. injection although the incorporation into the liver acid soluble- and RNA-fractions was somewhat delayed after the s.c. injection.This work was supported by grants from the Carl Trygger Foundation and the Foundation of Director Albert Påhlsson.