THE EFFECT OF COLD STRESS ON LYMPHOCYTE-PROLIFERATION IN FETAL ETHANOL-EXPOSED RATS

Prenatal ethanol exposure and stress have each been shown to have sign ificant effects on the immune system. This study examined the possible interactive effects of prenatal ethanol exposure and exposure to stre ss later in life on the immune system. Differential vulnerability to t hese challenges in female and male offspring was assessed. At 5 to 6 m onths of age, female and male offspring from prenatal ethanol-exposed (E), pair-fed (PF), and ad libitum-fed control (C) conditions were exp osed to 0, 1, or 3 days of cold (4 degrees C). At the end of the cold period, the proliferative response of splenic lymphocytes to the mitog ens concanavalin A (Con A) and pokeweed mitogen (PWM) was assessed. Th e data demonstrate a significant interactive effect between prenatal e thanol exposure and cold stress in female offspring. After 1 day of co ld stress, E females had significantly increased PWM-induced lymphocyt e proliferation compared with PF and C females, and significantly incr eased Con A-induced lymphocyte proliferation compared with PF females. There were no differences in PWM or Con A-induced lymphocyte prolifer ation among E, PF, and C females after 0 or 3 days of cold stress, nor among E, PF, and C males on any test day. Regardless of prenatal trea tment, females exposed to 1 or 3 days of cold had significantly greate r basal plasma corticosterone levels than females not exposed to cold. In contrast, only E males exposed to 1 or 3 days of cold had signific antly increased basal plasma corticosterone levels, compared with E ma les not exposed to cold; PF and C males showed no significant change i n basal corticosterone after cold stress. These data demonstrate that, in response to the challenge of cold stress, changes in lymphocyte pr oliferation to PWM and Con A may occur selectively in E females. Moreo ver, the interactive effects of prenatal ethanol and cold stress may r esult in enhanced rather than suppressed immune responsiveness.