Influences of maternal B₁₂ and methionine intake during gestation and lactation on testicular development of offspring in rats.

The influence of maternal vitamin B₁₂ malnutrition on testicular development of offspring was examined using soy protein-based B₁₂-deficient diets with or without 0.5% DL-methionine supplementation. Dams were fed the B₁₂-deficient diet throughout gestation and lactation, whereas dams in a control group were fed a control diet which contained cyanocobalamin in the B₁₂-deficient diet without methionine. Offspring born to dams fed the B₁₂-deficient diet without methionine showed poor testicular development, e.g. decreased numbers of seminiferous tubules containing healthy spermatocytes and a high ratio of apoptotic cells per all germ cells. The abnormality was rarely observed in the group fed the B₁₂-deficient diet with methionine. It was likely that the testicular abnormality of offspring was caused by B₁₂-deficiency post partum and was prevented by the methionine supplementation. These observations suggested that maternal B₁₂ nutritional status during the pre-weaning period is quite important for spermatogenesis of male offspring and that the requirement of B₁₂ for testicular development is to produce active B₁₂-dependent methionine synthase.