The observed increases in circulating LH and
FSH associated with flutamide treatment observed in the
current experiments are consistent with reduced negative
feedback at the hypothalamus with concomitant increased
trophic drive to the anterior pituitary. These data and the
changes in testicular expression of HSPA5, a known androgen
receptor-responsive gene, argue strongly that androgen receptor
antagonism was effective both systemically and locally
within the gonad.