Inhibition of the Sleep-Related Peak in Physiologic Human Growth Hormone Release by Somatostatin1

The synthetic linear tetradecapeptide, somatostatin, (125–250 μg bolus followed by constant infusion of 9–10 μg/min) was given over the first 90 min of sleep on 2 nights to each of 4 normal young men and on one night to an acromegalic patient. Complete inhibition of the sleep-related physiologic peak in nychthemeral hGH release was seen during infusion on all 8 nights in normal subjects and a 50% reduction was seen in the acromegalic. This occurred without alteration in sleep in the first cycle. Thus, potent SRIF activity in re physiologic and pathologic hGH release was exhibited by somatostatin.