“The Chl analog inhibited the release of LH and FSH by LHRH after addition prior to LHRH and after three changes of the incubation medium; in contrast, [Leu 2 , Leu 3 , D-Ala 6 ]-LHRH and [des-His 2 ]-LHRH only inhibit release when added together with LHRH.”