| Panceas is both an exocrine and endocrine organ which can secretepancreatic juice containing all kinds of digestive enzyme including hydrolystof carborhydrate protein and fat.Until now the problem about the control ofpancreatic exocrine secretion remains unclear which have an effect on therapyof pancreatic disease.Recently, parasympathetic (vagi) was thought to be veryimportant in the control of pancreatic exocrine secretion. The pancreaticsecretory response to intestinal nutrients was mediated by a complex interplayof neural and humoral mediators. The pancreatic enzyme response tointestinal perfusion with amino acid peptide and fatty acides is stronglyinhabited by atropine and vagotomy.And CCK and non-CCK-mediatedluminal stimuli evoke pancreatic enzyme secretion via stimulation of a vagalafferent pathway originating from the duodental muscosa.In addition, PP orTRH microinjection to DVC or DMN inhabits pancreatic secretion.DVCconsists of DMN AP and NTS,and NTS is projected by vagi. But it is notclear whether NTS takes part in mediating pancreatic exocrine secretion inCNS.The purpose of this study was to explore morphologic changes innucleus of solitary tract in rats when the duodenal stimulation of sodiumchloride increases pancreatic secretion . 1. The duodenal stimulation of sodium chloride induced c-Fosexpression in nucleus of solitary tract in rats This part was to investigate the activity of visceral sensory neurons innucleus of solitary tract after receiving the duodenal stimulation of sodiumchloride in rats. Rats were divided into five groups : NaCl(0.86mol/L),NaCl(0.15 mol/L), Deionized Water, 5-HT ( 10-4 mol/L ) and shamoperation.Immunhistochemical staining ,quantitative analysis of c-Fos wereachieved by IHN-Einvension method in all kinds of groups andregions(N1,N2,N3,N4,N5).The Result showed NaCl(0.86 mol/L) and 5-HT(10-4 mol/L) groups induced strong c-Fos like Immunoreactivity inNTS(P<0.01), compared with all the others.As for regions,compared with thegroup of NaCl(0.86 mol/L),the regions of N1 and N2 had strong c-Fosexpression in the group of 5-HT(P<0.05). The Result indicated NaCl(0.86mol/L) as the duodenal stimulation activated visceralsensory neurons inNTS.But NaCl(0.15 mol/L) and deionized water groups didn't activate theneurons in NTS. 2.Investigating the relation between c-Fos like neurons and substanc-e P receptor and measuring protein content of the pancreatic juice The part was to investigate the relation between c-Fos like neurons andsubstanc P receptor and to eluciate the increase of protein content inpancreatic juice when being given the duodenal stimulation.Those c-Fos likeneurons are activated by the duodenal stimulation of NaCl(0.86 mol/L) and5-HT(10-4 mol/L). Rats were divided into three groups : NaCl(0.86mol/L),5-HT(10-4 mol/L) and sham operation,being received above-mentionedstimulation and collected pancreatic juice every 15min. Double-labelimmunohistochemistry(immunoenzyme-fluorenscence) was performed forNK1-R and for c-Fos in all kinds of groups and regions(N1,N2,N3,N4,N5).Otherwise BCA Protein Assay was applied to measure protein content of thepancreatic juice.The result showed that NK1-R expressed the regions wherec-Fos expression was enhanced by duodenal stimulation of NaCl(0.86 mol/L)and 5-HT(10-4 mol/L) groups .But in the group of sham operation, there isno overlap between NK1-R and c-Fos expression. As for pancreatic juice,pancreatic protein secretion did not increase in the group of sham operationcompared with basal protein secretion(P<0.05).Infusion of NaCl(0.86 mol/L)and 5-HT(10-4 mol/L) increased pancreatic protein secretion over basal(P<0.05),and in 5-HT group pancreas secreted more protein than that inNaCl group. The results suggested that the duodenal stimulation ofNaCl(0.86 mol/L) and 5-HT(10-4 mol/L)probably activated NK1-R likeneurons and then induced increase of pancreatic protein secretion.Summary The purpose of this study... |
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