Lactation modifies stress-induced immune changes in laboratory rats.

Lactation and stressor exposure both influence the activity of the immune system, but the interaction of both factors on the immune defense is poorly understood. The aim was therefore to investigate in lactating Long-Evans rats the effect of social stress on aspects of cellular immunity in the blood and mesenteric lymph nodes (MLN). Acute social stress (2h) was induced in lactating and non-lactating female intruders using a confrontation model that yielded into social defeat and increased plasma corticosterone concentrations.