Effect of high thoracic segment epidural sympathetic nerve block on coronary microcirculation in rats with chronic heart failure

ZHU Yu; SHI Yan; ZHENG Jian-bin

doi:10.3969/j.issn.1672-5301.2024.01.016

Abstract：Objective To evaluate the effect of high thoracic segment epidural sympathetic nerve block(HTSB)treatment on coronary microcirculation in rats with chronic heart failure(CHF).Method Thirty male Wistar rats were randomly divided into the control,CHF and HTSB groups at Ningde Teachers College from June to September 2023,10 rats in each group according to the random number table method.The CHF rat model was established by subcutaneous injection of isoprenaline(ISO).HTSB was performed by injecting 0.2%ropivacaine through an epidural catheter.Coronary flow velocity reserve(CFVR),ejection fraction(EF),shortening fraction(FS),end-diastolic left ventricular internal diameter(LVDd)and end-systolic left ventricular internal diameters(LVDs)were measured.Serum nitric oxide(NO),creatine kinase(CK),malondialdehyde(MDA),superoxide dismutase(SOD),N-terminal pro-B-type natriuretic peptide(NT-proBNP),tumor necrosis factor-alpha(TNF-α),and interleukin-6 were detected using the corresponding kits.Western blot was performed to analyze the expression of relevant proteins.Results Compared to the control group,CFVR,EF and FS were significantly lower in rats in the CHF group[(3.27±0.61)vs.(2.51±0.65),(78.35±0.25)%vs.(53.58±6.75)%,(38.22±4.69)%vs.(24.37±3.18)%,P<0.05];compared to the CHF group,CFVR,LVDd and LVDs were significantly higher in rats in the HTSB group(P<0.05).Compared with the control group,serum CK,cTnI,NT-proBNP,TNF-α,IL-6 and MDA levels were significantly higher,while NO and SOD levels were significantly lower in rats in the CHF group(P<0.05);compared with the CHF group,serum CK,cTnI,NT-proBNP,TNF-α,IL-6 and MDA levels were significantly lower,while NO and SOD levels were significantly higher in the HTSB group of rats(P<0.05).Compared with the control group,the expression of inducible nitric oxide synthase(iNOS),intercellular adhesion molecule-1(ICAM-1)and P-Selectin were significantly elevated,while the expression of endothelial nitric oxide synthase(eNOS)was significantly reduced in the myocardial tissues of rats in the HTSB group(P<0.05);compared with the CHF group,the expression of iNOS,ICAM-1 and P-Selectin were all significantly lower,while the expression of eNOS was significantly higher in the HTSB group of rats(P<0.05).Conclusion HSTB treatment would improve coronary microcirculatory dysfunction in CHF rats,which may be achieved by inhibiting inflammatory response and oxidative stress,thus attenuating endothelial dysfunction.