| Objective:To discuss the regulation and control of IL-6 on Colonic propulsive movement of acute pancreatitis?AP?through L-type calcium channel.Methods:20 healthy male SD rats whose weight were 180220 grams were randomly divided into two groups,respectively,and the models of control group and AP group were made.The rats in the AP group were injected with 50 ug/kg of hyla peptide for 6 times in a row and at an interval of 1 hour.After the last injection of hyla peptide,one intraperitoneal injection of 10 mg/kg of lipopolysaccharide was conducted,while the rats in the control group had an intraperitoneal injection of saline with the same volume;The number of cacation grains of two groups of rats before 1 day of molding was recorded,and it was observed and recorded within 24 hours after molding.Then the number of cacation grains of two groups of rats and the spontaneous contraction change of the colon muscle strips were observed,and the colon of rats were taken to make longitudinal muscle strips.Later,the tonotransducer and biological function experiment system were used to record the spontaneous contraction of the muscle strips of the two groups,and the impact of longitudinal muscle strips after exogenous IL-6 treatmenton the spontaneous contraction intensity and contraction cycle;The pancreas of the two groups was observed with naked eyes,and at the same time,after HE staining,it was observed under a microscope.Then referring to the scoring criteria of Schmidt,the pancreatic histopathological score was conducted,and the differences between the two groups were compared.Later,serum IL-6 levels of two groups of rats were detected by enzyme-linked immunosorbent assay?ELISA?double-antibody sandwich method,and the differences between the two groups were compared.Then the distribution of IL-6 in the colon of two groups of rats was observed by immunohistochemical method after the intestinal content of colon samples were cleaned.Colonic smooth muscle cells were isolated by acute enzymatic digestion,and changes in peak current and current density of L-type calcium channel(ICa,L)in smooth muscle cells before and after exogenous IL-6 were detected by using whole-cell patch clamp technique.Results:The number of feces in the AP group was obvious less than that in the control group?P<0.0001?;The contraction amplitude of muscle strips in the AP group was smaller than that in the control group?P<0.05?,and the contraction period was longer than that in the control group?P<0.05?;Under the action of exogenous IL-6,the contraction cycle of muscle strips in the control group gradually extended from?115.6±7.547?s to?173.9±15.08?s?P<0.01?,but after the addition of exogenous IL-6,there was no effect on the spontaneous contraction amplitude of muscle strips;There were significant differences in the pancreatic histopathological score between the AP group and the control group?P<0.0001?.ELISA detection showed that serum IL-6 concentration in the AP group was significantly higher,and the difference was obvious significant?n=10,P<0.01?;The colonic immunohistochemistry of the two groups of rats showed that the expression of IL-6 in the colon of the control group was more widely,while there was a significant expression in intestinal glands,mucosa and submucosa of the AP group;After the effect of exogenous IL-6 on colon smooth muscle cells,the peak currentICa,L was still around 0mV,but the current density decreased from?-3.344±0.432?pA/pF to?-2.317±0.390?pA/pF,and the difference was statistically significant?P<0.001?by comparing with itself.Conclusions:?1?IL-6 may be associated with prolonged colonic contraction of the AP;?2?IL-6may regulate colonic motility by inhibiting L-type calcium channel activity. |
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