Light-dark and feeding regimens affect circadian phasing of blood-ethanol decay rates.
Rats maintained on a 12 hour:12 hour light-dark cycle, with food continuously available, exhibited a prominent and reproducible circadian rhythm in the slope of the linear blood-ethanol clearance curve. Peak values fell near the end of the dark period and trough values late in the light period. These phase relationships persisted with 4, 8 and 12 hours phase shifts of the illumination schedule. However, when food availability was restricted to 4 hours per day the feeding regimen became the dominant synchronizer for the rhythms in blood-ethanol decay rate and body core temperature. With resumption of the ad lib feeding regimen, the L-D cycle again entrained these rhythms. Ethanol injections (1.5 g/kg, IP) did not alter the expected excursion of the circadian temperature curve, as measured 4 hours after dosing.
D000818:Animals; D001831:Body Temperature; D002940:Circadian Rhythm; D000431:Ethanol / Q000097:blood*; D005247:Feeding Behavior; D005508:Food Deprivation; D008027:Light; D008297:Male; D051381:Rats; D013997:Time Factors
D000431:Ethanol