although the hypothalamic content of gnrh was unaltered by 4-app treatment , the decrease in pituitary gnrh receptors observed in vivo , together with the fall in circulating lh and fsh and retention of gonadotropin responses to gnrh stimulation , suggest that the primary effect of 4-app is to inhibit gnrh synthesis and/or release from the hypothalamus .
C0023610
gnrh
C0020663
hypothalamus