Vasoactive intestinal polypeptide decelerates nonrem-rem cycles and modulates hormone secretion during sleep in men . Murck, H., J. Guldner, M. Colla-M[umlaut]uller, R. M. Frieboes, T. Schier, K. Wiedemann, F. Holsboer, and A. Steiger. Max Planck Institute of Psychiatry, Clinical Institute, Department of Psychiatry, D-80804 Munich, Germany
APStracts 3:0122R, 1996.
Centrally administered vasoactive intestinal polypeptide (VIP) promotes rapid-eye-movement (REM) sleep in rats, rabbits and cats. We studied the effect of 4 x 10 [mu]g VIP (experiment 1, n = 7) and of 4 x 50 [mu]g VIP (experiment 2, n = 10) administered hourly as intravenous boluses between 22:00 and 01:00 h on the sleep EEG and on secretion of plasma ACTH, cortisol, growth hormone and prolactin in humans. In experiment 2 the sleep cycles were decelerated during the first three cycles due to increased duration of both REM sleep and nonREM sleep periods and there was a tendency to increased REM:nonREM ratios. With the low VIP dosage prolactin levels were decreased during the whole night whereas with the high dosage they were increased during the first half of the night. In experiment 2 the cortisol nadir was advanced, after midnight the serum cortisol levels were enhanced and the growth hormone peak was blunted. It appears that VIP may have a phase-advancing effect on sleep cycles and on cortisol secretion, possibly through actions that involve the suprachiasmatic nucleus.

Received 28 April 1995; accepted in final form 22 March 1996.
APS Manuscript Number R257-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 1 April 96