Prenatal stress alters immune function in the offspring of rats.

Pregnant rats were either exposed to restraint under bright lights for 45 min three times daily (n = 7) or were left undisturbed (n = 8) during Days 14-21 of gestation. Offspring were tested for cellular immune responses as measured by Concanavalin A-stimulated proliferation and Natural Killer (NK) cytotoxicity of splenocytes as juveniles or adults, or were tested for specific humoral immune responses to in vivo challenge with the antigen Keyhole Limpet Hemocyanin (KLH) as adults. Results indicated that: (a) Proliferation did not vary as a function of sex or prenatal treatment in either juvenile or adult offspring; (b) in juveniles NK cytotoxicity was marginally lower in males as compared to females, and was also marginally reduced by prenatal stress in males but not females, whereas in adults, NK cytotoxicity was marginally enhanced by prenatal stress in both sexes; and (c) prenatally stressed offspring of both sexes had higher levels of anti-KLH antibodies as compared to controls.