Growth hormone-releasing hormone antibodies suppress sleep and prevent enhancement of sleep after sleep deprivation.
Previous reports suggest that the hypothalamic growth hormone-releasing hormone (GHRH) promotes sleep, especially non-rapid-eye-movement sleep (NREMS). To evaluate the role of endogenous GHRH in sleep regulation, the effects of antibodies to rat GHRH (GHRH-ab) were studied on normal sleep, brain temperature (Tbr), and GH secretion in experiment I and on enhanced sleep after sleep deprivation in experiment II. In experiment I, affinity-purified GHRH-ab (50 and 200 micrograms) raised in goats and a control goat immunoglobulin G (IgG) preparation were injected intracerebroventricularly (icv) in rats 1 h before the onset of the light cycle, and sleep-wake activity and Tbr were recorded for the next 12 or 23 h. Both doses of GHRH-ab suppressed NREMS and REMS throughout the light cycle. Sleep durations at night were normal. Electroencephalographic (EEG) slow-wave activity, characterized by EEG slow-wave amplitudes, was reduced after GHRH-ab during both the light and the dark cycles. Plasma GH concentrations measured 6-12 h after injection of GHRH-ab (200 micrograms) were diminished. Both the control IgG and GHRH-ab elicited fever. In experiment II, the sleep-wake activity and Tbr of rats were recorded for 24 h in three experimental conditions: base-line with icv injection of IgG, 3-h sleep deprivation with icv IgG injection, and 3-h sleep deprivation with icv GHRH-ab (200 micrograms). After sleep deprivation (+IgG), a prompt increase in EEG slow-wave activity (power density analysis) and late increases in NREMS and REMS durations were found.(ABSTRACT TRUNCATED AT 250 WORDS)
Obál
F
F
Department of Physiology and Biophysics, University of Tennessee, Memphis 38163.
Payne
L
L
Opp
M
M
Alföldi
P
P
Kapás
L
L
Krueger
J M
JM
D000818:Animals; D000906:Antibodies / Q000008:administration & dosage / Q000276:immunology*; D001831:Body Temperature; D001921:Brain / Q000502:physiology; D013006:Growth Hormone / Q000378:metabolism; D013007:Growth Hormone-Releasing Hormone / Q000276:immunology*; D007276:Injections, Intraventricular; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000502:physiology*
D000906:Antibodies; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone