The pituitary-gonadal response to the gonadotrophin releasing hormone analogue D-Ser (TBU)6-Des Gly10-LHRH-ethylamide in normal men.

We have studied the dose-response characteristics of the LHRH analogue D-Ser (TBU)6-Des Gly10-LHRH-ethylamide administered subcutaneously to five normal male volunteers. The relative potency of the analogue is about sixty times (FSH) and forty times (LH) that of the parent peptide and the increased potency and duration of action of the analogue lead to enhanced biological effect in terms of testosterone release. The prolonged duration of action of the analogue suggests that a single daily dosage regime could be used although further chronic studies with this potent analogue should be undertaken in normal volunteers to determine optimum dosage schedules.