Elevated Concentrations Of Ascorbate And Normoxia Suppress Testosterone Production In Cultured Guinea Pig Leydig Cells

Elevated concentrations of ascorbate and normoxia suppress testosterone production in cultured guinea pig Leydig cells by Mark A. Kukucka and Hara P. Misra Department of Biomedical Sciences Virginia-Maryland Regional College of Veterinary Medicine Virginia Polytechnic Institute & State University, Blacksburg, VA 24061 ABSTRACT In recent years, several metabolic roles have been proposed for vitamin C. Recent information suggests a strong causal relationship between high endogenous levels of ascorbic acid and changes in normal reproductive biology. Using highly enriched populations of guinea pig Leydig cells, we have found that elevated levels (50 to 500 microM) of ascorbate significantly (P < 0.01) depressed testosterone production in a dose-dependent manner while low levels (0 to 10 microM) were without effect. Leydig cells incubated under hypoxic (3% oxygen) culture conditions produced significantly (P < 0.01) more testosterone than similar cells cultured under normoxic (19% oxygen) conditions. The results of this study suggest that high concentrations of ascorbate and normoxic culture conditions suppress testosterone production in isolated Leydig cells. Thus, it would seem that there exists a delicate balance between normal metabolic requirements for vitamin C and excessive ascorbate levels that might alter normal gonadal reproductive events. citation Kukucka, Mark A. and Hara P. Misra. 1994. Elevated concentrations of ascorbate and normoxia suppress testosterone production in cultured guinea pig Leydig cells. Reprod Toxicol 8(4):333-9.