Effects of maternal immobilization stress on birth weight and glucose homeostasis in the offspring.

Recent epidemiological studies have shown strong associations between low birth weight and the incidence of diabetes in the adult offspring. It has been hypothesized that exposure to maternal glucocorticoids programs cellular changes in the fetus which increases the susceptibility of the offspring to diabetes. Stressors produces large increases in maternal glucocorticoids. The present study determined the effects of immobilization stress during weeks one, two or three of pregnancy on offspring birth weight, glucose homeostasis, and the ability of the offspring to cope with metabolic stress. Immobilization stress produced large increases in maternal levels of ACTH and corticosterone, but did not affect birth weight of the pups. Chronic administration of high fructose diet, a metabolic stressor, to 60 days old control and prenatally stressed offspring produced large increases in plasma levels of triglyceride and insulin. However, there were no differences between the groups either in peak levels, or in the rates of increase and decrease (upon discontinuation of the diet) of plasma triglyceride and insulin concentrations. Basal levels of glucose and insulin, and areas under the glucose and insulin plasma concentration-time curves after an i.p. glucose dose were similar between 120 days old control and prenatally stressed offspring. These results suggest that in young adult rats prenatal immobilization stress did not affect glucose homeostasis or the ability of these rats to cope with chronic metabolic stress.