ABSTRACT
Objective To explore the relationship between the content of neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), inducible nitric oxide synthase (iNOS) and the changes of the corresponding receptors in myocardial tissue and the development of heart failure. Methods Doxorubicin was used to prepare rat heart failure models(10 rats), control group (10 rats), Cardiac ultrasound testing evaluated its cardiac function, the distribution of nerve fibers was detected by nerve staining kit method, the tissue expression levels of NPY, CGRP, iNOS and neuropeptide Y receptor Y1 (NPY1R), receptor activity modifying protein 1 (RAMP1), guanylate cyclase beta 1(GCYB1) were observed by immunofluorescence and immunohistochemical staining method. Western blotting was used to detect the protein expression levels of NPY, CGRP, iNOS and NPY1R, RAMP1, GCYB1 receptors in myocardial tissue. Results Compared with the control group, the protein expression level and tissue expression distribution of CGRP in the myocardial tissue of the heart failure group were significantly decreased (P<0.05), while the density of nerve fibers, the protein expression level and tissue expression distribution of NPY and iNOS were significantly increased (P<0.05). The protein expression levels of GCYB1 and RAMP1 in myocardial tissue of the heart failure group were significantly increased, while the protein expression levels of NPY1R were significantly decreased (P<0.05). Conclusion Heart failure can lead to remodeling of the content and distribution of nerve fibers, CGRP, NPY, iNOS and their receptors in myocardial tissue, which may be one of the causes of cardiac innervation disorders.
ABSTRACT
Objective To investigate the expression of elastin and collagen in heart of rats with chronic heart failure and their related proteases. Methods Sprague-Dawley rat model of chronic heart failure was made by intraperitoneal injection of doxorubicin hydrochloride. Examination of cardiac function by echocardiography. ELISA and immunohistochemistry were used to detect brain natriuretic peptide ( BNP) , and Masson staining was used to detect myocardial fibrosis. The mRNA levels of elastin, I /IH collagen were detected by Real-time PCR and the expression levels of elastin, I/IH collagen, Matrix metalloproteinase (MMP)-2 and MMP-9 were detected by Western blotting. Results Compared with the control group, the heart function of rats in the model group decreased, the BNP content in serum increased, the expression of BNP in myocardial tissue was strongly positive, and the mRNA and protein expression of elastin decreased. Nevertheless, the mRNA and protein expression of I / IH collagen increased. At the same time, both MMP-2 and MMP-9 protein expression levels increased in model rat heart. Conclusion Heart failure leads to decreased expression of elastin, I /IH collagen expression increased, and the MMP-2 and MMP-9 may be involved in the regulation of this process.