The level of protein and type of fat in the diet of pregnant rats both affect lymphocyte function in the offspring

Female rats were fed throughout pregnancy on diets which differed in the le vel of protein (90 or 180 g/kg) and the type of fat (100 g corn oil or 50 g corn oil + 50 g coconut oil or 10 g corn oil + 90 g coconut oil/kg) they c ontained. At birth they were transferred to standard laboratory chow. Thymo cytes from neonates exhibited a strong proliferative response to the T-cell mitogen concanavalin A, whereas spleen lymphocytes did not. Lower protein intake during pregnancy impaired neonatal thymocyte proliferation by up to 80%. Thymic and spleen lymphocyte proliferation remained impaired at weanin g for the offspring of darns fed the lower protein diet containing 100 or 5 0 g corn oil/kg. Lymphocytes from the offspring of dams fed the lower prote in diet containing 90 g coconut oil/kg responded in a similar fashion to ce lls from the offspring of dams fed the diets containing 180 g protein/kg. T hus, the acquisition of lymphocyte responsiveness which was impaired at bir th after prenatal exposure to a low protein diet could be overcome postnata lly if the prenatal diet included a large amount of coconut oil and a small amount of corn oil. Spleen natural killer cell activity at weaning was low er following prenatal exposure to the low protein diet and was lower when c oconut oil was included in the diet. Thus, some aspects of immune function are programmed in utero by factors related to the diet of the mother. The e ffects of the nutrients and other factors received during suckling and of t he developmental changes in the immune system which occur postpartum appear unable to overcome the impact of the diet received in utero. (C) 2000 Else vier Science Inc.