Changes Of VIP And NOS Immunoreactive Neurons In Ileum Myenteric Ganglia In SAP Rats With Gastrointestinal Dysmotility

Objective:To study the changes of VIP and NOS immunoreactive neurons in ileum myenteric ganglia of SAP rats with gastrointestinal dysmotility. Methods:Twenty Sprague Dawley rats were randomly divided into two groups: sham operated group(n=10) and SAP group(n=10). SAP model was established by retrograde injection of 5%sodium taurocholate into the bile-pancreatic duct. The rats in sham operated group had sham operation without bile-pancreatic duct infusion.24 h after the injection, small intestine propulsion ratio and pathological damage of pancreas were measured. Pancreas was collected for HE staining and pathological evaluation. Whole-mount samples of ileum myenteric ganglia were prepared and double immunofluorescence was employed to observe VIP and NOS immunoreactive neurons in the ganglia. The percentages of VIP and NOS immunoreactive neurons in total neurons were calculated. Results:In the sham operated group, thepercentages of VIP and NOS immunoreactive neurons in ileum myenteric ganglia were(8.48 ± 1.06)% and(29.04 ± 3.36)%, respectively. In the SAP group, the percentages of VIP and NOS immunoreactive neurons in ileum myenteric ganglia were(14.22 ± 2.12)% and(40.55 ± 2.59)%,respectively. In the SAP group, small intestine propulsion ratio was decreased significantly,(30.20 ± 3.82)% vs(51.37 ± 5.04)%, P<0.01. But the histological score of the pancreas was increased,(13.78 ±0.65)% vs(3.74 ± 0.23)%,P<0.01. There was a negative correlation between the percentages of VIP-IR neurons and small intestine propulsion ratio,(r=-0.771,P<0.05). There was a negative correlation between the percentages of NOS-IR neurons and small intestine propulsion ratio,(r=-0.779,P<0.05). There was a negative correlation between the histological score of the pancreas and small intestine propulsion ratio(r=-0.893,P<0.05).Conclusion:Plasticity took place in VIP and NOS neurons in ileum myenteric ganglia of SAP rats with gastrointestinal dysmotility. The gastrointestinal dysmotility in SAP maybe related to the increases of VIP and NOS immunoreactive neurons in myenteric ganglia.