Circadian rhythm of corticosterone in mice: The effect of chronic consumption of alcohol

Abstract

The effect of chronic consumption of alcohol on the circadian variations of the plasma corticosterone investigated in DBA/2J male mice. After 15 weeks of alcohol consumption (3.8%w/v for the first week and 7.5% for subsequent weeks) the alcohol groups exhibited a flattened circadian corticosterone curve, the level being intermediate between the peak and trough values of the water control groups. The diurnal patterns of food and liquid consumption were still present at the 10th week of alcohol treatment in the alcohol groups, although the absolute amount of food and liquid consumed at each of the 6-h intervals was somewhat different between the alcohol and water groups. The blood alcohol showed a peak at early morning with the mean of 100 mg/100 ml, but the levels of alcohol during the remaining periods were remarkably stable, the means ranging from 30 to 46 mg/100 ml. Chronic consumption of alcohol, even relatively low concentrations, appears to affect the neural sites in the CNS controlling the circadian rhythm of ACTH release.

Chronic Alcohol Consumption in Rats Leads to Desynchrony in Diurnal Rhythms and Molecular Clocks

“…In alcoholics, normal, overall elevated, and sporadic diurnal rhythms of cortisol have all been reported (Bertello et al, 1982;Margraf et al, 1967;Stokes, 1973). In mice, blunted diurnal CORT rhythms along with dampened amplitude have been seen after chronic alcohol (Kakihana and Moore, 1976;Sipp et al, 1993), findings consistent with our results in rats. Moreover, we found that chronic alcohol in rats advanced the molecular clock (Per1) in the adrenal and pituitary glands, yet the SCN was unaffected.…”

“…Abnormalities in diurnal rhythms of blood pressure, body temperature, and hormone secretion (e.g., cortisol, melatonin, and testosterone) have been reported in alcoholics (Bertello et al, 1982;Kawano et al, 2002;Wasielewski and Holloway, 2001). Disrupted diurnal rhythms of corticosterone (CORT) after chronic alcohol have also been observed in rodents (Kakihana and Moore, 1976). The sleep and circadian dysfunctions after chronic alcohol may result from disturbed sleep homeostasis or disrupted circadian rhythms or very likely a combination of both, but the exact mechanism remains unclear at present.…”

Chronic ethanol intake modulates photic and non-photic circadian phase responses in the Syrian hamster

“…On the other hand, previous studies show that even prolonged exposure to ethanol results in little or no metabolic or functional tolerance, and does not produce signs of dependence or a physical withdrawal syndrome, in this species (Harris et al, 1979;Kulkosky and Cornell, 1979;McMillan et al, 1977;Piercy and Myers, 1995). Indeed, the greater ethanol intake in hamsters relative to rats appears to be largely due to the much higher rate of ethanol metabolism in the former species (Kulkosky and Cornell, 1979), so it not surprising that blood alcohol levels seen in the present study were modest and variable, and very similar to mid-dark-phase levels seen in previous studies of 24-hour free-choice intake in ethanol-preferring rats (Aalto, 1986;Agabio et al, 1996;Murphy et al, 1986) and mice (Kakihana and Moore, 1976;Millard and Dole, 1983). …”

The Role of Clock in Ethanol-Related Behaviors

“…Physiological, behavioral, and molecular rhythms are all affected by rewarding stimuli, including drugs of abuse and food. Rodent studies have shown that prolonged alcohol treatments can disrupt the circadian pattern of a variety of hormonal and behavioral rhythms (Kakihana and Moore, 1976;Kosobud et al, 2007, Madeira et al, 1997Rajakrishnan et al, 1999;Rosenwasser et al, 2005;Spanagel et al, 2005a). However, the molecular mechanisms of these disruptions are yet to be determined.…”