LEFT-VENTRICULAR HYPERTROPHY IN SPONTANEOUSLY HYPERTENSIVE RAT - EFFECTS OF ACE-INHIBITION ON MYOCARDIOCYTE ULTRASTRUCTURE

The aim of this study is to investigate the effects of two ACE-inhibit ors with different chemical formulae, cilazapril (CLZ) and captopril ( CPT), on left ventricular myocardiocytes from spontaneously hypertensi ve rats (SHR), characterized by ultrastructural alterations associated with left ventricular hypertrophy, and from Wistar-Kyoto (WKY) rats, considered as controls. After CLZ-treatment, not remarkable changes ar e observed in WKY myocardiocytes, whereas SHR ones show a considerable reduction in their original alterations in ultrastructure. After CPT- treatment, both SHR and WKY myocardiocytes are altered in ultrastructu re. The morphometric investigation confirms that CPT and CLZ produce d ifferent effects. Even if the drugs induce a similar decrease in blood pressure and left ventricular mass index, CLZ unlike CPT seems to imp rove the ultrastructural abnormalities associated with left ventricula r hypertrophy. These changes could be related to the different chemica l structure of CLZ and CPT, or to a different affinity of the two drug s for the local renin-angiotensin system.