Cortisol treatment of neonatal rats: effects on enzymes in kidney, liver and heart.

Cortisol treatment of neonatal rats did not have permanent effects on the levels of 2-7 enzymes in heart, kidney, brain, and liver, even though some exhibited abnormally high concentrations during the first 1 or 2 weeks. An injection of cortisol at birth evoked premature rises of glucose-6-phosphatase (G6P-ase) in kidney, of soluble and particulate aspartate aminotransferase (AAT) in kidney and heart and of soluble AAT in liver. These enzymes (with the exception of soluble AAT in the female) did not respond to cortisol in adult rats. The significance of the varying effects of cortisol is discussed in relation to previously studied developmental enzyme formations.