Pancreatic HB9 protein level is affected by early life stress in young adult rats: possible involvement of TNF-α and corticosterone.

This study examined foot shock stress effects, during weaning, on pancreatic HB9 protein expression in young adult male rats in the presence or absence of adulthood stress. The pups were divided into Control, Early life stress, Young adult stress, and Early + young adult stress groups. Plasma corticosterone, insulin, glucose, and TNF-α concentrations, and pancreatic HB9 protein expression were assessed. At 2 weeks of age, stress increased plasma corticosterone level. During young adulthood, plasma TNF-α and glucose concentrations increased, whereas plasma insulin and pancreatic HB9 protein levels decreased in Early life stress group. Whereas, Early + young adulthood stress group showed no change in the study parameters, except for plasma corticosterone and insulin concentrations. Overall, early life stress reduced pancreatic HB9 protein expression possibly by elevating plasma corticosterone and TNF-α levels in early life and adulthood, respectively. However, combined with adulthood stress, HB9 protein expression increased to the level of Control.