The effects of prenatal exposure to structurally diverse chemicals on the ontogeny of rat dehydrogenases.

Activity levels of sorbitol dehydrogenase (SDH), lactate dehydrogenase (LDH), and glucose-6-phosphate dehydrogenase (G6PDH) were measured in the livers and brains of rats treated prenatally with 3,4,3',4'-tetrachlorobiphenyl (4CB, 3 mg/kg/day), diethylstilbestrol (DES, 10 micrograms/kg/day), zeranol (ZN, 4mg/kg/day), and cadmium (Cd, 25 mg/kg/day) and compared with enzyme levels for control groups. Enzyme activities were measured at days 15, 17, 19, and 21 prenatally, and days 1, 5, 10, 21, 35, and 56 postnatally. SDH activity was not altered by treatment with 4CB, DES, or ZN, but Cd produced reduced levels in both liver and brain of sexually mature offspring. The patterns of LDH and G6PDH, including sexual differentiation of the latter in adult liver, were not affected by any of the treatments in either tissue. The developmental profiles of each of these enzymes in untreated animals is unique, suggesting that a similar catalytic mechanism is not a factor in determining the patterns of their developmental accumulation.