Sex and strain differences in ethanol drinking: effects of gonadectomy.
BACKGROUND
Alcohol drinking behavior in rats is known to be sexually dimorphic and strain-dependent.


METHODS
To test whether the gonadal steroid milieu exerts activational effects on ethanol intake and can modulate individual sensitivity toward alcohol use and misuse, we examined the effects of gonadectomy on oral self-administration (OSA) of ethanol in male and female rats from different strains. After castration, animals were given continuous free choice between water and ethanol solutions. The ethanol concentration was progressively increased from 2% to 10% and maintained at 6% (the preferred concentration) for 24 days. Ethanol solutions were then withdrawn for 9 days. During the second phase of free-choice drinking, the ethanol concentration was gradually increased every 4 days by the following amounts, in order as listed: 6%, 12%, and 24%.


RESULTS
Our results confirm both gender and strain differences in ethanol drinking: females exhibited higher ethanol intake than males, and the WKHA strain drank more than the WKY and SHR strains. However, except for a small decrease in ethanol drinking during the acquisition of ethanol OSA in males after castration, no clear-cut difference was found between gonadectomized and sham-operated animals during the maintenance of ethanol OSA behavior.


CONCLUSIONS
These data suggest that gender and strain differences observed are insensitive to gonadal steroids during adulthood, and that different sensitivities to the effect of gonadal steroids do not explain the sex x strain interaction observed in ethanol drinking.
Cailhol
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S
Laboratoire de Neurogénétique et Stress, INSERM U.471-INRA-Institut François Magendie, Bordeaux Cedex, France.
Mormède
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P
D000428:Alcohol Drinking / Q000378:metabolism / Q000523:psychology*; D000818:Animals; D005260:Female; D012739:Gonadal Steroid Hormones / Q000378:metabolism; D008297:Male; D009919:Orchiectomy / Q000523:psychology*; D010052:Ovariectomy / Q000523:psychology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012646:Self Administration / Q000523:psychology; D012737:Sex Factors; D013045:Species Specificity
D012739:Gonadal Steroid Hormones