EFFECTS OF PRENATAL ETHANOL EXPOSURE AND STRESS IN ADULTHOOD ON LYMPHOCYTE POPULATIONS IN RATS

The present study was undertaken to assess the possible interactive ef fects of prenatal ethanol exposure and stress in adulthood on lymphocy te populations in rat offspring, and to examine differential vulnerabi lity of males and females to these challenges. Male and female offspri ng from prenatal ethanol-exposed (E), pair-fed, and ad libitum-fed con trol conditions were exposed to a 3-week chronic intermittent stress r egimen in adulthood. Animals were exposed to two of six different stre ssors daily, one each at random times in the morning and afternoon, wi th the same pair of stressors being repeated every 4 days. Following t he 3-week stress period, lymphocytes from four compartments (periphera l blood, spleen, thymus, and cervical lymph nodes) were analyzed for e xpression of differentiation antigens. Data demonstrate that, whereas a number of the effects of prenatal ethanol on lymphocyte populations appeared to be nutritionally mediated, the additional challenge of exp osure to stressors differentially affected animals exposed to ethanol prenatally and appeared to have effects primarily in male offspring. S tressed E males had a greater reduction in the number of pan T-cells i n the thymus and peripheral blood, compared with nonstressed E males, but showed an increased peripheral blood pan T-antigen expression. Str essed E males also had reduced numbers of peripheral blood CD4(+) T-ce lls and thymic CD4(+)CD8(+) T-cells, compared with controls. In additi on, several effects of stress were observed in animals in all three pr enatal treatment groups, including decreased numbers of lymph node pan T- and CD4(+) T-cells and decreased numbers of total peripheral blood lymphocytes in males, increased numbers of total splenic acid thymic lymphocytes in females, and increased numbers of splenic CD8(+) T-cell s, as well as a decreased ratio of CD4(+):CD8(+) T-cells in the lymph node and spleen in both males and females. These findings indicate tha t, although exposure to chronic intermittent stress in adulthood may h ave marked effects on lymphocyte populations across all treatment grou ps, specific deficits in the immune system of fetal E animals may beco me apparent only when these animals are subjected to the additional ch allenge of stress. Moreover, male and female offspring may be differen tially affected by the two challenges of ethanol and stress.