Effects of indole-pyruvic acid on sleep and food intake in the rat.
Indole-pyruvic acid was studied for its short- and long-term effects on electroencephalographic sleep and on food intake in rats implanted with cortical and muscular electrodes. Following a single injection, indole-pyruvic acid (10-50 mg kg-1 i.p.) reduced by 16-23 min (range) the latency of the first slow-wave episode in a dose-related fashion and produced a significant increase in slow-wave sleep time (12-40%) in doses of 10-30 mg kg-1. Rapid eye movement sleep latency and rapid eye movement sleep time were increased (by 23-37 min) and reduced (57-71%) respectively. The effects of indole-pyruvic acid on slow-wave sleep time were still present after 3, 7 and 14 days of chronic administration (10 mg kg-1 day-1), whereas tolerance to the effect of indole-pyruvic acid on rapid eye movement sleep was observed. Daily food consumption was reduced (20-28%) by acute administration of indole-pyruvic acid (15-30 mg kg-1 i.p.), but tolerance developed after 5 days of repeated injections. These findings are in accordance with previous evidence suggesting that indole-pyruvic acid effects may be related to the activation of central serotonin neurons, which are involved in the inhibitory control of sleep and food intake.
Merlo Pich
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Institute of Human Physiology and Endocrinology, University of Modena, Italy.
Solfrini
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V
Biagini
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Fuxe
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K
Agnati
L F
LF
D000818:Animals; D004326:Drinking / Q000187:drug effects; D004435:Eating / Q000187:drug effects*; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012890:Sleep / Q000187:drug effects*; D013997:Time Factors
D007211:Indoles; C008122:indol-3-yl pyruvic acid