An international website dedicated to providing current information on news, reports, publications,and peer-reviewed research articles concerning alcoholism and alcohol-related problems throughout the world.
Postings are provided by international contributors who monitor news, publications and research findings in their country, geographical region or program area of interest.
All postings are entered without editorial or contributor opinion or comment.
To support the free and open dissemination of research findings and information on alcoholism and alcohol-related problems. To encourage open access to peer-reviewed articles free for all to view.
For full versions of posted research articles readers are encouraged to email requests for "electronic reprints" (text file, PDF files, FAX copies) to the corresponding or lead author, who is highlighted in the posting.
Saturday, April 28, 2012
Social rank, chronic ethanol self-administration, and diurnal pituitary–adrenal activity in cynomolgus monkeys
This study aimed to determine whether diurnal pituitary–adrenal hormonal rhythms account for differences between social ranks in ethanol self-administration or are differentially affected by ethanol self-administration between social ranks.
During alternating individual (n = 11–12) and social (n = 3 groups) housing of male cynomolgus monkeys (Macaca fascicularis), diurnal measures of cortisol and adrenocorticotropic hormone (ACTH) were obtained from plasma samples three times per week. Social rank was determined, ethanol (4 %, w/v) self-administration was induced, and then the monkeys were allowed a choice of water or ethanol for 22 h/day for 49 weeks.
For all social ranks, plasma ACTH was elevated during social housing, but cortisol was stable, although greater among dominant monkeys. Ethanol self-administration blunted the effect of social housing, cortisol, and the diurnal rhythm for both hormones, regardless of daily ethanol intake (1.2–4.2 g/kg/day). Peak ACTH and cortisol were more likely to be observed in the morning during ethanol access. Ethanol, not vehicle, intake was lower during social housing across social ranks. Only dominant monkeys showed significantly lower blood–ethanol concentration during social housing.
There was a low threshold for disruption of diurnal pituitary rhythms by ethanol drinking, but sustained adrenal corticosteroid rhythms. Protection against heavy drinking among dominant monkeys may have constrained ethanol intoxication, possibly to preserve dominance rank.