LEFT-VENTRICULAR HYPERTROPHY AND ITS RELATION TO THE CARDIAC KININ-FORMING SYSTEM IN HYPERTENSIVE AND DIABETIC RATS

We investigated the cardiac tissue kallikrein and kininogen levels, le ft ventricular wall thickness and mean arterial blood pressure of Wist ar Kyoto and spontaneously hypertensive rats with and without streptoz otocin-induced diabetes. The mean arterial blood pressure was highly e levated (P<0.001) in Wistar Kyoto diabetic and spontaneously hypertens ive diabetic rats as compared with their respective controls. The card iac tissue kallikrein and kininogen levels were reduced significantly (P<0.001) in diabetic Wistar Kyoto, spontaneously hypertensive and dia betic spontaneously hypertensive compared with Wistar Kyoto control ra ts. In addition, the left ventricular thickness was found to be increa sed (P<0.001) in diabetic Wistar Kyoto and spontaneously hypertensive rats in the presence and in the absence of diabetes. Our results indic ate that reduced activity of the kinin-forming system may be responsib le for inducing left ventricular hypertrophy in the presence of raised mean arterial blood pressure in diabetic and hypertensive rats. Thus, the kinin-forming components might have a protective role against the development of left ventricular hypertrophy. The possible significanc e of these findings is discussed. (C) 1998 Elsevier Science Ireland Lt d.