Abstract:

Objective
To study the effect of growth hormone relasing peptide(GHRP) on the IL-1β level in myocardium tissue of chronic heart failure(CHF) rats and to discuss the relative mechanism.Methods 30 healthy male Wistar rats were randomly divided into normal group(n=10),model group (n=10) and treatment group (n=10).The CHF models were set up by injecting adriamycin,the hemodynamic changes were observed and the pathological changes of the myocardium tissue of rats were observed by HE staining;the morphological changes of myocardial cells were detected by electron microscope;the changes of the forms and the mean density of immunological positive cells of IL-1β  were detected by immunohistochemistry method;the changes of the contents of IL-1β in myocardial tissue of rats were detected by ELISA method.Results Compared with normal group,the heart rates,the arterial pressures and the maximum change rates of left ventricle pressure in model group were  decreased significantly(P<0.05);the indexes mentioned above in treatment group were a little lower than those in normal group,but there were no significant difference(P>0.05).The myocardial cells in model group arranged irregularly and presented inflammatory invasion;the morphological changes of myocardial cells in treatment group presented little compared with normal group.The electron density of intercalated disc in model group was decreased,and the mitochondrial appeared swelling and vacuolar degeneration in many regions;whereas the mitochondrial in treatment group kept original structure and the swelling and vacuolar degeneration appeared in a few regions.The immune-positive cells in model group tended to be hypertrophy,and the cells showed a phenomenon of aggregation,but the positive cells in treatment group were reduced significantly and showed a phenomenon of scatteration;the mean density of expression of IL-1β in model group was obviously higher than those in normal group and treatment group(P<0.05),the mean density of expression of IL-1β in treatment group was a little higher than that in normal group,but there was no significant difference(P>0.05).The content of IL-1β in myocardial tissue in model group was higher than those in normal group and treatment group obviously(P<0.05);the contents of IL-1β in treatment group were a little higher than those in normal group (P>0.05).Conclusion GHRP can decrease
the content of IL-1β in myocardium tissue and  improve the myocardial cells remodeling  in  CHF rtas.

Key words: chronic heart failure;growth hormone releasing peptide;interleukin-1β