The Effect Of Acetylcholine And M Type Acetylcholine Receptors On Myocardial Injury In Septic Rats

Objectives The SD rats sepsis model was made by cecal ligation and puncture(CLP).We observed the change of acetylcholine and muscarinic acetylcholine receptor in ratsmyocardium tissue, and their influence to pathomorphism and prognosis of sepsis-induced myocardial injury, which provides the theory basis for clinical treatment.Methods36male SD rats were randomly divided into three groups: normal control(12rats), sham operated control(12rats) and CLP (sepsis) group(12rats). Normal controlgroup were given no disposal; Cecal ligation and puncture was done in the sepsis group,and laparotomy only in the sham operated control. During the experiment, generalconditions of rats were observed,which include anal temperature, heart and breathingrates. At6hours after modeling, the blood samples were obtained to detect theconcentrition of cTnT and CK, CK-MB by ELISA and automatic biochemical analyzer.Ventricular myocardium was cut down from the isolated heart, and then devided into2group: one was stated by method of HE stain to observe pathologic change; another wasfixed by4%paraformaldehyde and4%glutaraldehyde and were observed throughelectronic microscopy, then mitochondrion were analyzed by Flameng semiquantitativeevalution. The rest myocardium tissue were prepared to tissue homogenate and detectedacetyl choline and muscarinic acetylcholine receptor by ELISA. The date was presentedas mean±standard deviation and data analysis was performed by using SPSS18.0, thenadopted one-way ANOVA, A P value of<0.05was considered statistically significant.Results1In CLP group, the rats showed different degrees of sepsis such as drowsinessand an increase in body temperature, heart rate and breathing rate, while normal controland sham operated control groups were symptom-free.2Compared with normal controland sham operated control groups, the concentrations of cTnT, CK-MB, CK and acetylcholine in CLP group were significantly higher (P<0.05), with statistical significance.However, the concentrations of muscarinic acetylcholine receptor were not significantdifference (P>0.05).3The rats mycardial tissue samples were observed after HE stainedby microscope, implying edema and inflammatory cell infiltration only founded in CLPgroup. Under electron microscope, swelling and vacuolization in mitochondria,cristaefractured and disorganized and decreased matrix density were observed in CLP group. What’s more,compared with normal group and sham group myocardial mitochondriasemi-quantitative score increased significantly (P <0.05).Conclusions1The concentration of cTnT, CK and CK-MB in sepsis increases, withstatistical significance as compared with the control group.2There are obvious injuries ofmyocardium in sepsis, which illustrate that myocardial injury has already existed in theearly stage.3The increase of acetyl choline is a major cause of mycardial andmitochondrial injuries in sepsis heart.4The concentrations of muscarinic acetylcholinereceptor were not significant change in sepsis myocardial tissue, which imply that theeffect of sepsis to muscarinic acetylcholine receptor is under further investigation.