Liver enzyme adaptation after lithium administration in handled and nonhandled rats.

We have examined the interaction of lithium administration and the infant stimulation procedure of handling on hormonally regulated enzymes of liver. Animals handled in infancy show an increased morning corticosterone level in response to lithium feeding and markedly elevated serum glucose during refeeding following a two day fast, when compared to non-handled control animals. Lithium alters serum corticosterone both in response to the stress of fasting, and during the diurnal cycle following glucose refeeding. The handled and non-handled animals respond differently. These results are consistent with previously reported alterations in feedback regulation of ACTH secretion in handled animals. They also indicate a further modification of this system in response to lithium administration.