| Background: Multiple organ dysfunction syndrome (MODS) is a clini-calsyndrome, which can be induced by severe trauma, infection, major operation and shock.In MODS there are two or more organs dysfunction simultaneously or successively.MODS is characterizing with hypermetab-olizability, hyper-circulation, immoderateand out of controlled infla-mmatory response and organ dysfunction, and is a maincause of the death of patients with abdominal surgical diseases. The gastrointestinaltract is considered the initiation and target organ in MODS. Recovering ofgastrointestinal motility can effectively inhibit the development of MODS. Interstitialcells of cajal (ICC) is the pacemaker cell of the gastrointestinal tract, distributing widelyin the gastrointestinal tract. ICC connects with others to form network-like struction,produce and condunt the slow wave. Therefore, ICC can control the rhythms ofgastrointestinal contraction. ICC is also the medium of nerve singal conveying from theenteric nerve system (ENS) to the smooth muscle cell (SMC) in gastrointestinal tract.Therefore, in present study view, ENS, ICC and SMC connected each other to formnetwork struction, and constitute the basic functional unit ofgastrointestinal motility(BFUGM). ENS-ICC-SMC network has important relationship with gastrointestinalmotility dysfunction.Objective: To make the model of multiple organ dysfunction syndrome (MODS)in rats induced with bacterial peritonitis, observe the apoptosis and morphologicalchanges in intestinal enteric nerve-interstitial cells of Cajal-smooth muscle cells(ENS-ICC-SMC) network, and detect the changes of intracellular and extracellularsignaling pathways, apoptotic pathway and expression of apoptosis related proteins in rats with MODS, and the preventive and therapeutic effects of Da-Cheng-Qi Decotion.Methods: One hundred Wistar rats of both sexes，weighing200to250g，wererandomly assigned to three groups: control group (n=20), MODS group (n=40) andtreated group (n=40). The rats in MODS model group and treated group were injectedEscherichia coli (E. coli) suspension into abdominal cavity under sterile condition. Thetreated group was gavaged with Da-Cheng-Qi Decotion two days before the E. colisuspension was injected. Twenty-four hours after injection, the proximal segment ofintestine was resected and studied by transmission electron microscope, TUNEL,immunohistochemistry, immunofluorescence and confocal laser scanning microscopy,observing the morphological changes and apoptosis of small intestinal ENS, ICC andsmooth muscle in rats with MODS, detecting signal pathway, apoptosis pathway andexpression of apoptosis related proteins, and the preventive and therapeutic effect ofDa-Cheng-Qi Decotion.Results: Observation of small intestinal morphology and expression of cytokinesin muscular layer: Compared with control group, the small intestinal morphology in ratswith MODS was disorder, with massive inflammatory cells infiltrating. The expressionsof CGRP, HSP70and TGF-β1were increased significantly (P<0.05). Compared withMODS group, small intestine was minor injury in treated group, a spot of inflammatorycells infiltrating. The expressions of CGRP, HSP70and TGF-β1were reducedsignificantly (P <0.05).Observation of intestinal nerve system: Compared with the control group, thenumber of neurons, the expressions of NGF and ACh/SP/VIP/NO/caveolin-1insignaling transduction pathway were significantly reduced in rats with MODS. Whereas,the apoptotic number of neurons, the expressions of Bax/Bcl-2in mitochondrialapoptotic pathway and PKA/PKC in protein kinase apoptotic pathway weresignificantly increased (P<0.05). Compared with MODS group, the numbers of neurons,the expressions of NGF and ACh/SP/VIP/NO/caveolin-1in signaling transductionpathway were significantly increased in treated group. On the other hand, the apoptoticnumber of neurons, the expressions of Bax/Bcl-2in mitochondrial apoptotic pathwayand PKA/PKC in protein kinase apoptotic pathway were significantly reduced (P<0.05).Observation of intestinal ICC: Compared with the control group, the apoptoticnumbers of ICC, the expression of Bax/Bcl-2in mitochondrial apoptotic pathway andPKA/PKC in protein kinase apoptotic pathway were significantly increased in rats with MODS. Whereas, the expression of caveolin-1was significantly reduced (P<0.05). Theultrastructure of ICC was obviously destroyed. Compared with MODS group, theapoptotic number of ICC, and the expression of Bax/Bcl-2in mitochondrial apoptoticpathway and PKA/PKC in protein kinase apoptotic pathway were significantly reducedin treated group. On the other hand, the expression of caveolin-1was significantlyincreased (P<0.05). The ultrastructure of ICC was obviously recovered.Observation of intestinal SMC: Compared with the control group, the apoptoticnumber and index of SMC, and the expressions of COX-2/NF-κB/P53were allsignificantly increased. The expressions of Bax/Bcl-2/Cyt C/caspase-9/caspase-3inmitochondrial apoptotic pathway, Fas/Fasl in death receptor pathway, and PKA/PKC inprotein kinase apoptotic pathway showed the same trend. Whereas, the number of SMC,and the expressions of SM actin and ACh/NO/SP/VIP/CX45/caveolin-1in signalingtransduction pathway were all significantly reduced. The expressions of IP3R and RyRshowed the same trend (P<0.05). Compared with the MODS group, the apoptoticnumber and index of SMC, and the expressions COX-2/NF-κB/P53were allsignificantly reduced. The expressions of Bax/Bcl-2/Cyt C/caspase-9/caspase-3inmitochondrial apoptotic pathway, Fas/Fasl in death receptor pathway, and PKA/PKC inprotein kinase apoptotic pathway showed the same trend. Whereas, the number of SMC,and the expressions of SM actin and ACh/NO/SP/VIP/CX45/caveolin-1in signalingtransduction pathway were all significantly increased. The expressions of IP3R and RyRshowed the same trend (P<0.05).Observation of intestinal ENS-ICC-SMC network: Compared with the controlgroup, the numbers of ENS, ICC and SMC were significantly reduced in MODS group(P<0.05). The ultrastructure of ENS-ICC-SMC was obviously destroyed. Comparedwith the control group, the numbers of ENS, ICC and SMC were significantly increasedin treated group (P<0.05). The ultrastructure of ENS-ICC-SMC was obviouslyrecovered.Conclusions: Gastrointestinal tract was markedly dilated and mortality was highin rats with MODS. The increased expression of CGRP and TGF-β1in small intestinalmuscle layer might cause inflammation and stress reaction in intestinal muscle, whilestimulated up-regulation of HSP70expression to protect itself. Da-Cheng-Qi Decotioncould significantly reduce the mortality of rats with MODS, promote the recovery ofgastrointestinal motility. Da-Cheng-Qi Decotion could inhibit of inflammatory andstress response in small intestine muscle tissue, through down-regulating the expressions of CGRP and TGF-β1. This made HSP70expression down-regulate, andprotect the contractile function of small intestinal smooth muscle.Under MODS station, activation of mitochondrial and protein kinase apoptoticpathway, damage of intracellular and extracellular signaling pathways, anddown-regulation of NGF expression resulted in increased apoptotic number of intestinalneuron, and morphological structure was destroyed. Da-Cheng-Qi Decotion couldinhibit apoptosis and injury of intestinal neuron, repair morphological structure of ENS,and promote the recovery of gastrointestinal motility, maybe through inhibitingactivation of mitochondrial and protein kinase apoptotic pathways protect signaltransduction pathway and expression of NGF.In rats with MODS, the apoptotic number of ICC was increased, and network wasdamaged. This might be caused by ultrastructure damaging, activation of mitochondrialand protein kinase apoptotic pathways, down-regulation of caveolin-1expression.Da-Cheng-Qi Decotion could inhibit apoptosis and network damage of ICC, byprotecting ultrastructure and caveolin-1expression of ICC, and inhibiting activation ofmitochondrial and protein kinase apoptotic pathways.In rats with MODS, the apoptotic number of SMC was increased, andmorphological structure was obviously damaged. This might be caused by reduction ofSM actin and IP3R/RyR expression, up-regulation of COX-2/NF-κB/P53expressions,activation of mitochondria/death receptor/protein kinase apoptotic pathways, anddestruction of signal transduction pathway. Da-Cheng-Qi Decotion could protect SMactin and IP3R/RyR expressions, inhibit activation of mitochondria/deathreceptor/protein kinase apoptotic pathways, down-regulate expressions ofCOX-2/NF-κB/P53, protect signal transduction pathway. This might result in inhibitionof SMC apoptosis, and promotion of gastrointestinal motility recovery.In rats with MODS, the network damage of ENS-ICC-SMC might be caused byinjury of ultrastructure, the reduced number of ENS, ICC, and SMC. Da-Cheng-QiDecotion could protect network ultrastructure of ENS-ICC-SMC, inhibit the cellnumber reduction of ENS, ICC, and SMC, to recover network structure ofENS-ICC-SMC and promote gastrointestinal movement. |
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