Abstract
Hypothalamo-hypophyseal portal blood has been collected from conscious OVX ewes by a procedure that permits maintenance of pituitary function. GnRH was measured in portal plasma and LH was measured in peripheral (jugular) plasma. The data demonstrate exact synchrony of GnRH and LH secretion. We conclude that each pulsatile LH secretory episode results from a pulsatile discharge of GnRH from the hypothalamus via the portal network