Protect effect of Intermedin_(1-53) on isoproterenol-induced ischemic injury in rats heart / 中国药理学通报

ABSTRACT

Aim Observe the effects of IMD_ 1-53 on acute myocardial injury induced by isoproterenol (ISO). Methods Myocardial ischemia injury in rats was induced by subcutaneous injection with ISO(50 mg?kg -1?d -1, 2days ), and the therapeutic effect of IMD_ 1-53 was observed. Cardiac function was measured. Myocardial cAMP content was determined by radioimmunoassay (RIA). The gene expression of calcitonin receptor-like receptor (CL) and receptor-activity-modifying protein (RAMP1), RAMP2 and RAMP3 in ventricular was determined by semi-quantitative RT-PCR analysis. IMD receptors in cardiac sarcolemmal membrane fractions were assayed [ 125I]-IMD binding studies. Results ISO-treated rats showed lower maximal rate of increase and decrease of left-ventricle pressure development (?LVdp/dt_ max) and higher left-ventricle end-diastolic pressure (LVEDP; all P