[Increased and prolonged release of lh and fsh on intravenous administration of a synthetic analogue of lh-rh [d-ser(tbu)6-ea10-lh-rh] in healthy men of various age groups (author's transl)].

Healthy male subjects of various age groups respond to the administration of D-Ser(TBU)6-EA10-LH-RH, an analogue of LH-RH substituted in positions 6 and 10, by a prolonged and increased release of LH and FSH. Increased serum concentrations of LH and FSH were observed 20 minutes after intravenous administration of the compound. Maximum concentrations of LH and FSH were seen after 60, and 60 to 240 minutes, respectively. Serum concentrations of both gonadotropins remained elevanted for up to 8 hours after the administration of 10 microgram of the LH-RH analogue. A dose response relationship was observed with regard to the serum concentrations of LH and FSH over the range of 1.25 to 5.0 microgram of the LH-RH analogue. The administration of 10 or 20 microgram of the compound, however, did not cause a further rise in plasma FSH, although the release of LH was further enhanced.