Angiotensin II type 2 receptors participate in the regulation of inflammatory cytokine secretion in adult rat hypertrophied cardiomyocytes / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of angiotensin II (AngII) type 2 (AT2) receptors on pressure overload-induced inflammatory cytokine secretion in adult rat hypertrophied cadiomyocytes.</p><p><b>METHODS</b>Rat models of left ventricular hypertrophy induced by pressure overload was established by placing a band around the abdominal aortic of the rats, from which the hypertrophied cadiomyocytes were isolated and purified 8 weeks later. The isolated cardiomyocytes were treated with AngII plus losartan or AngII plus PD123319, and 36 h after the treatments, the expression levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta) and IL-6 in the supernatant were detected using radioimmunoassay.</p><p><b>RESULTS</b>AngII induced TNF-alpha and IL-1beta secretion from the hypertrophied cardiomyocyets, and pretreatment of the cells with PD123319, but not losartan, decreased their secretion. IL-6 level was not detected in the supernatant.</p><p><b>CONCLUSION</b>AngII-induced the expression of inflammatory cytokines in adult rat hypertrophied cardiomyocytes is mediated mainly by AT2, not by AT1 receptors.</p>