Elevated concentrations of ascorbate and normoxia suppress
testosterone production in cultured guinea pig Leydig cells.
Reprod Toxicol. 1994 Jul-Aug;8(4):333-9.
Kukucka, Mark A. and Misra, Hara P.
Department of Biomedical Sciences, Virginia-Maryland Regional College
of Veterinary Medicine, Virginia Polytechnic Institute & State
University, Blacksburg 24061-0442.
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.