CGRP protects the intestinal barrier by reducing intestinal apoptosis in sepsis rats

Objective To investigate the mechanism of calcitonin gene-related peptide (CGRP) in protecting intestinal barrier integrity by reducing intestinal apoptosis in sepsis rats. Methods Thirty SD male rats were randomized into 5 groups (n=6): Normal group, sham group, sepsis group (CLP group), CGRP treatment group (CGRP group) and anti-CGRP group. Rats were injected with 0.5 ml CGRP (30 μg/kg) in the CGRP group and injected with 0.5 ml CGRP (30 μg/kg) and 0.5 ml CGRP8-37 (30 μg/kg) in the anti- CGRP group. Serum diamine oxidase (DAO) and D-lactic acid levels were measured 30 minutes before the operation and 48 hours after the modeling. Histopathological changes of the small intestine were observed by HE staining; apoptosis of small intestine was detected by TUNEL assay; the expression of phosphorylated Bcl-xl/Bcl-2 related death promoter (p-BAD), phosphorylated extracellular signal-regulated kinase (p-ERK), caspase-3 were observed by immunohistochemistry. Results Compared with the normal group, the small intest