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Effect of Postnatal Exposure of Female Rats to An Alcohol Diet: Influence of Age and Circulating Sex Steroids
Author(s) -
Lee Soon,
Rivier Catherine
Publication year - 1994
Publication title -
alcoholism: clinical and experimental research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 153
eISSN - 1530-0277
pISSN - 0145-6008
DOI - 10.1111/j.1530-0277.1994.tb00072.x
Subject(s) - endocrinology , medicine , alcohol , ovariectomized rat , hypothalamus , ethanol , sexual maturity , hormone , biology , biochemistry
We have previously reported that when compared with animals fed ad libitum, adult ovariectomized (OVX) female rats fed an alcohol diet, but not its isocaloric equivalent control, showed a blunted ACTH response to the intravenous injection of interleukin‐1β (IL‐1β). The present work was undertaken to determine whether this finding could be extended to intact rats, and whether the stage of sexual maturation and/or circulating sex steroids of ovarian origin modulated the inhibitory influence of alcohol. Intact female rats were exposed to alcohol or pair‐fed between postnatal days 25–35 (group 1), 35–45 (group II), or 45–55 (group III). Animals of comparable age and fed ad libitum served as controls. All alcohol‐exposed animals had similar blood alcohol levels measured during the eighth night of treatment. Group I lost the most weight following exposure to alcohol, but did not show measurable changes in ACTH released in response to 20 or 100 ng IL‐1β/kg. Both alcohol and pair‐feeding caused a modest decrease in IL‐1‐stimulated ACTH in rats of group II, but only alcohol significantly blunted corticotrophs' activity in group III. Group III, when fed alcohol, also showed lower CRF content in the median eminence compared with absolute controls or the isocaloric diet. No measurable changes, however, were observed in steady‐state CRF mRNA levels in the hypothalamus of animals fed any of the diets. When intact and OVX rats were compared at 55 days of age, alcohol feeding caused a decrease in IL‐1‐induced ACTH secretion which was slightly, though not significantly, larger in intact animals. We conclude that in female rats, circulating sex steroids of ovarian origin may modulate the ability of an alcohol diet to blunt the response of the corticotrophs to peripherally administered IL‐1β. As blood‐born cytokines are believed to stimulate ACTH secretion by acting at the level of peptide terminals in the median eminence, the finding of alcohol‐induced decreases in CRF content in this region suggests that the drug alters peptide release from nerve terminals. Whether sex steroids interact with alcohol at that level or through other mechanisms remains to be determined.