Normal levels of hepatic drug-metabolizing enzymes in neonatally induced, growth hormone-deficient adult male and female rats.

The effects of chronic growth hormone deficiency on the growth hormone-dependent, sexually dimorphic hepatic drug-metabolizing enzymes were studied in adult rats of both sexes. Neonatal administration of monosodium L-glutamate produced the expected syndrome characterized by stunted growth, obesity, prolonged vaginal estrus, and an inhibition in the growth of the pituitaries, adrenals, gonads, sexual accessory organs, and kidneys. Associated with these abnormalities was a 90% reduction in the concentration of serum growth hormone in male and female rats. In contrast, the activities of hepatic aniline hydroxylase, total cytochrome P-450, and the Michaelis constants and maximal velocities for hexobarbital hydroxylase and UDP-glucuronosyltransferase were unaffected by the profound deficiency in growth hormone.