Impairment of CRH in the intestinal mucosal epithelial barrier of pregnant Bama miniature pig induced by restraint stress.

Female, especially for pregnant female, are vulnerable to psychological stress. The morphology and metabolism of the maternal intestine are both obviously changed during pregnancy, thus making intestinal health status more fragile under psychological stress. The aim of the present study was to investigate the role of CRH and CRHR1 in the pregnant maternal intestine under psychological stress, thus exploring the mechanism of psychological stress in the pregnant maternal intestine. Bama miniature pigs were divided into the control and restraint stress groups from the first day of pregnancy. After restraint stress treatment for 18 consecutive days (D18), the plasma, duodenum, jejunum, ileum and colon were collected for study. Pregnant Bama miniature pigs subjected to restraint stress had significantly elevated CRH, adrenocorticotropic hormone (ACTH) and cortisol (COR) levels in plasma. Consistent with the increase in CRH levels, we observed enhanced oxidative stress levels in the intestine, which resulted in intestinal mucosal injury, including impaired intestinal morphology, a reduced number of goblet cells and proliferating cell nuclear antigen-positive cells, decreased expression of MUC2 and tight junctions, and elevated expression of CRHR1 and caspase-3. Moreover, exogenous CRH could directly promote IPEC-J2 cell apoptosis and influence its cell cycle (S and G2 phase) through CRHR1, and antalarmin could alleviate this phenomenon. Therefore, our results illustrated that the intestinal dysfunction of pregnant Bama miniature pigs was caused by restraint stress, and these changes were associated with the enhanced expression of CRH and CRHR1 in the intestine.