The Pituitary-testicular Response to Luteinising Hormone Releasing Hormone Administration to Normal Men*

Abstract
The response of the pituitary and testis in normal men to the injection of LH-RH has been studied using single intravenous doses of either 25 mug or 100 mug. Serum LH levels rose with both doses but significant elevation of plasma testosterone was evident only following 100 mug of LH-RH. Though testosterone levels were elevated within 60 minutes, peak responses occurred from 4-12 hours post-injection. The rise in serum FSH levels was small or absent at 25 mug but was clearly present following 100 mug LH-RH, in general rising more slowly than LH levels but persisting for a longer period.