Background & objectives:Cardiac ankyrin repeat protein(CARP) is an embryonic protein which increases its expression on myocytes in pressure overloaded conditions and failing heart. Adriamycin(AD), a cardiotoxic chemotherapeutic agent, suppresses CARP expression. We compared expression of CARP in cardiac tissues of normotensive rats and spontaneously hypertensive rats(SHR) with AD-induced cardiomyopathy. Materials & methods:Normotensive Wistar-Kyoto rats(WKY) and SHR were divided into AD-treated and saline-treated groups. AD(2.5mg/kg) was injected 6 times intraperitoneally for 3 weeks. Transthoracic echocardiography was performed to confirm dilated cardiomyopathy, 3 weeks after last injection. Rat CARP was obtained from cloning of CARP cDNA and injected to rabbit, then CARP antibody was extracted from rabbit serum. Immunohistochemical stain was performed with extracted CARP antibody on left ventricles of four groups and CARP expression was quantified by measuring CARP volume fraction(CVF) using image analysis program(ImagePro-Plus 4.5). Results:1.CARP was expressed diffusely in cytoplasm.(Figure) 2.CVF was 5.96짹5.11% in WKY and 9.04짹6.26% in SHR.(p=0.014) 3.CVF was 2.26짹4.74% in AD-treated WKY and 1.24짹4.32% in AD-treated SHR.(p=0.32) 4.AD-treated groups showed significantly decreased CARP expression, compared to saline-treated groups.(p<0.001, p<0.001 respectively). Conclusion: This results suggest CARP is closely related to the pathogenesis of AD-induced cardiomyopathy and especially, has a pivotal role of AD cardiac toxicity in hypertensives.