Mitsuo Sakato

Cardiotonic agent SCH00013 prolongs survival of cardiomyopathic hamsters.

&NA; The authors examined the effects of long‐term treatment with SCH00013, a novel cardiotonic agent with calcium‐sensitizing action, on survival of hereditary cardiomyopathic BIO 14.6 hamsters. Sixty‐nine male hamsters at 223 days of age were divided into untreated, SCH00013‐low (approximately 1 mg/kg/d), and SCH00013‐high (approximately 10 mg/kg/d) groups. Survival curves were constructed in the three groups. The first deaths in the untreated, SCH00013‐low, and SCH00013‐high groups were found at 263, 290, and 314 days of age, respectively. A 50% mortality rate was observed at 392 days in the untreated group, 396 days in the SCH00013‐low group, and 445 days in SCH00013‐high group. The survival time distribution of the SCH00013‐high group was significantly different from that of the untreated group (P < 0.005). However, histomorphometric examinations revealed that the degree of progression of calcification and fibrosis in the ventricular wall of the BIO 14.6 hamsters was not different between the untreated and SCH00013‐treated groups. Plasma concentration of this agent was 2 &mgr;M at the end of the second week of continuous administration via drinking water in SCH00013‐high group. Thus, SCH00013 was beneficial for the survival of cardiomyopathic hamsters, suggesting that this agent is a possible candidate for the treatment of chronic heart failure.