EXPRESSION OF THE TYPE-1 AND TYPE-2 STEROID 5-ALPHA-REDUCTASES IN HUMAN FETAL TISSUES

Androgens play a key role in human fetal development. Therefore, it is important to understand the distibution of the isozymes of 5 alpha-re ductase, the enzyme that converts testosterone to the more potent andr ogen, dihydrotestosterone. The expression of the two isozymes of 5 alp ha-reductase was studied in human fetal skin and fetal prostate by mea suring the in vitro enzyme activity in crude preparations. Low levels of the type 1 5 alpha-reductase were found in fetal scalp and back ski n. Studies with fetal prostate samples confirmed that the type 2 enzym e is expressed in levels similar to those found in adult tissues. Thes e results provide the first evidence that both isozymes of 5 alpha-red uctase are expressed during human fetal development. (C) 1995 Academic Press, Inc.