Sleep, clonidine, and their interactive effect on growth hormone secretion in normal men.
Central alpha 2-adrenergic function is often inferred from the growth hormone (GH) response to clonidine, despite the drug's known hypnotic effect and the accepted cholinergic mechanism for sleep-related GH secretion. We examined the effect of daytime sleep on GH secretion in normal men taking placebo or clonidine orally, using a two-group blind design (placebo, clonidine; n = 9 each). Each subject participated in two morning sessions monitored by polysomnography: wake (sleep actively prevented) and sleep (subjects asked to sleep for 3 hr after receiving placebo or clonidine). Blood samples were drawn at times -15 min, 0, and every 30 min for 3 hr after the test dose was given. The total sleep time was similar for both groups. The placebo/wake group had lower GH responses than the other three groups. None of the GH responses in the clonidine/sleep group were significantly different from those in the placebo/sleep group; and the peak GH micrograms/L, mean +/- SD) was 16.9 +/- 10.9 vs. 14.6 +/- 10.5, respectively. We conclude that the GH response to clonidine may not be indicative of alpha 2-adrenergic function if sleep is permitted during the test.
Cavallo
A
A
Department of Pediatrics, E.P. Bradley Hospital, Brown University, East Providence, Rhode Island 02915.
Carskadon
M A
MA
Rosekind
M R
MR
Cattell-Harvey
G
G
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D002986:Clinical Trials as Topic; D003000:Clonidine / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D008297:Male; D010919:Placebos; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology
D010919:Placebos; D013006:Growth Hormone; D003000:Clonidine