This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by PIZARRO, M. Articles by GURPIDE, E. Search for Related Content PubMed PubMed Citation Articles by PIZARRO, M. Articles by GURPIDE, E.

Compartmentalization of Testosterone and Androstenedione in Guinea Pig Testis^*

Departments of Physiology and Medical Biochemistry, Université Catholique de Louvain B-1200 Brussels, Belgium
the Departments of Obstetrics and Gynecology and Biochemistry, Mount Sinai School of Medicine New York, New York 10029

Address requests for reprints to: Dr. Erlio Gurpide, Department of Obstetrics and Gynecology, Mount Sinai School of Medicine, 100th Street and Fifth Avenue, New York, New York 10029.

Abstract

Decapsulated guinea pig testes were superfused with a mixture of [³H]testosterone (T) and [¹⁴C]androstenedione (A). Steady state isotopic data from these experiments were used to estimate, among other parameters, the uptake of steroids, the tissue concentrations of labeled T and A derived from each of the superfused tracers, and the ratio of labeled T and A released by the tissue to the medium.

Concentrations of endogenous T and A were measured in testicular samples and, after supervision of decapsulated testis with buffer without steroids, in tissue and superfusate.

The ratios of concentrations of T and A in tissue as well as of T and A released to the medium were not the same for labeled (exogenous) and unlabeled (endogenous) steroids. These findings indicate that superfused tracers do not adequately reflect the fate of the endogenously produced androgens.

The results from this study can be interpreted on the basis of a model representing two or more spaces of distribution of T and A not equally accessible to endogenous and exogenous androgens. One of these spaces may correspond to Leydig cells, in which synthesis and interconversion of endogenous T and A occur, and the other may correspond to cellular elements in the seminiferous tubules where most of the exogenous labeled T and A but only part of the endogenously produced androgens are metabolized in vitro.

Footnotes

^* This work was supported by Grants M74.04C of the Population Council, HD-07197 of the NIH, and 20.019 from Fonds National de la Recherche Scientifique Medicale (FRSM, Belgium).

Received March 14, 1977.