Dehydroepiandrosterone, pregnenolone and sex steroids down-regulate reactive astroglia in the male rat brain after a penetrating brain injury

Astrocytes are a target for steroid hormones and for steroids produced by t he nervous system (neurosteroids). The effect of gonadal hormones and sever al neurosteroids in the formation of gliotic tissue has been assessed in ad ult male rats after a penetrating wound of the cerebral cortex and the hipp ocampal formation. The hormones testosterone, 17 beta-estradiol and progest erone and the neurosteroids dehydroepiandrosterone, pregnenolone and pregne nolone sulfate resulted in a significant decrease in the accumulation of as trocytes in the proximity of the wound and in a decreased bromodeoxyuridine incorporation in reactive astrocytes. Of all steroids tested, dehydroepian drosterone was the most potent inhibitor of gliotic tissue formation. These findings suggest that neurosteroids and sex steroids may affect brain repa ir by down-regulating gliotic tissue. (C) 1999 ISDN. Published by Elsevier Science Ltd. All rights reserved.