Chymase inhibitor improves survival in hamsters with myocardial infarction.
Ключавыя словы
Рэферат
The purpose of the present study was to assess the effects of chronic treatment with an orally active chymase inhibitor, 4-[1-(naphthylmethyl)benzimidazol-2-ylthio]butanoic acid (TEI-E548), in a hamster myocardial infarction model. In the first experiment, after confirming the biochemical inhibitory action of TEI-E548 on human and hamster chymases (Ki = 6.2 and 30.6 nM, respectively), the biological action of TEI-E548 in vivo was assessed by the inhibition of hamster chymase-induced microvascular leakage. In the second experiment, myocardial infarction was produced by coronary artery ligation in male Syrian hamsters. TEI-E548 (0.1% containing chow) was given 24 h after surgery and continued for 3 or 5 weeks, while the control and sham-operated groups were fed a standard chow. The survival rate was assessed in each group. At the end of each study period, blood pressure was measured at the left hind-limb, the heart rate and cardiac function were measured by echocardiography, the end-diastolic pressure by a direct catheterization, and organ weights and biochemical parameters, including plasma renin and angiotensin-converting enzyme activities and plasma angiotensin I and angiotensin II concentrations, were measured. In the first experiment, a standard chow containing 0.1% TEI-E548 completely inhibited the hamster chymase-induced microvascular leakage. In the second experiment, TEI-E548 treatment significantly increased the survival rate (37% versus control), and attenuated cardiac hypertrophy (13% versus control) and end-diastolic left ventricular pressure (34% versus control), but it did not decrease the infarction size nor improve the ejection fraction. The plasma angiotensin II concentration post-myocardial infarction was significantly suppressed by TEI-E548 throughout the study period. We conclude that TEI-E548 is an orally active useful chymase inhibitor and improves survival and cardiac hypertrophy of the post-myocardial infarction hamster.