Evaluation of tissue kallikrein activity on survival time after acute coronary artery ligation in hypertensive rats

Abstract

It is known that the tissue kallikrein–kinin system is located in the cardiac tissue, and the lack of this system in the cardiac tissue might induce cardiac dysfunctions. In this study, we investigated the potential role of tissue kallikrein and Trasylol, an inhibitor of tissue kallikrein, on survival time with acute left coronary artery ligation for 15 min in spontaneously hypertensive rats (SHR). Tissue kallikrein (8 and 16 μg/kg, i.v.) treatment caused significant ( P<0.05) increases in the survival time of SHR as compared with the saline-treated control SHR. Trasylol pretreatment abolished ( P<0.05) the beneficial effect on tissue kallikrein on survival time. The ligation of coronary artery resulted in significant ( P<0.05) reduction in systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) of SHR compared with the saline-treated control SHR. The tissue kallikrein treatment caused greater ( P<0.001) reduction in the SBP, DBP and HR of SHR, when the mean values were compared between before coronary artery ligation and after coronary artery ligation. Trasylol (6 μg/kg) treatment antagonized the effects of tissue kallikrein associated with survival time, SBP, DBP and HR. These findings may suggest that tissue kallikrein is able to act as a cardioprotective agent as demonstrated by the increase in survival time of SHR with acute coronary artery ligation. The significance of these observations is discussed.