Pregnant rats were fed an ethanol diet from the first day of pregnancy until parturition. Control rats were either pair fed with an isocaloric sucrose diet, or fed with standard lab chow (basic control group). Rats fed with the ethanol diet and their pair-fed controls showed a similar increase in body weight during pregnancy, which was lower than the increase observed in the basic control group. At 10 days after ethanol withdrawal all three groups presented similar body weights. A lower body growth was exhibited by the offspring of both the ethanol and the sucrose pair-fed rats, implicating a prenatal nutritional factor on the postnatal growth. Furthermore, the rate of body growth was lower in the offspring of the ethanol-treated animals than in the offspring of both their pair-fed and the basic control rats, indicating the presence of an additional ethanol-associated factor. On day 4 of development, the concentration of beta-endorphin peptides (pmol/mg protein) in the pituitary gland and the anterior lobe, of the offspring of the ethanol-treated animals and their sucrose pair-fed controls, was significantly higher than that of the offspring of the basic control animals. However, a lower content of beta-endorphin-like peptides was noticed in the whole pituitary gland, the anterior lobe, and the intermediate lobe of the offspring of the ethanol-treated rats and their pair-fed controls on days 8, 14, and 22 postnatally.(ABSTRACT TRUNCATED AT 250 WORDS)