Chronic Stress Effects on Adrenal Cortex Cellular Proliferation in Pregnant Rats

Chronic stress by immobilization during pregnancy may cause alterations in mechanisms maintaining homeostasis in the adrenal gland. The objective of this study was to quantify cellular proliferation index in the adrenal cortex during pregnancy second half and assess the effects of chronic stress on it. Adrenal cortex proliferation index in stressed rats showed a significant decrease at 12 and 17 days of gestation, while at day 21 it did not show differences with the control treatments. Moreover, proliferation index of reticular zones in control and experimental rats, exhibited a significant reduction in comparison to glomerular and fascicular zones of adrenal cortex during the three gestation days studied. In conclusion, chronic stress by immobilization produces a decrease in cellular proliferation index at 12 and 17 gestation days, which may be related to changes in plasmatic concentrations of corticosterone and prolactin and, to the reduction of specific growth factors. Furthermore, the observed proliferation diminishment in reticular zone regarding the other cortical zones would be consistent with the migration theory of adrenal cells.