Alterations in neurosteroid levels may play a role in affective disorders including those related to changes in the levels of ovarian steroids. The effects of pregnancy and delivery on circulatory and brain levels of dehydroepiandrosterone (DHEA), pregnenolone (PN), their sulfate esters and the enzymatic activities of sulfatase and sulfotransferase were examined in rats. Our findings indicate an increase, not reflected in the brain cortex, in serum DHEA levels, at the end of pregnancy with a partial decrease following delivery. DHEA sulfate levels in the cortex and PN levels in both serum and cortex decreased following delivery with no changes in its sulfated form. Sulfatase levels were high both before and after delivery with no changes noted in sulfotransferase levels, compared to controls. We speculate that changes in the level or ratio of sulfated and free neurosteroids may play a role in postpartum behavioral disorders due to their antagonistic GABA(A) modulatory effect.
Copyright 2004 S. Karger AG, Basel