International Journal of Cardiology, 2 (1983) 339-345 Elsevier Biomedical Press 339 Dilazep -induced reduction of ischemic necrosis in rats with coronary artery occlusion Massimo Chiariello, Gregorio Brevetti, Arturo Genovese, Alessandro Cataffo, Giuseppe Ambrosio and Mario Condorelli Institute of Medical Pathology, University of Naples, 2nd School of Medicine, Naples, Italy (Received 20 October 1981; revision received 16 April 1982; accepted 10 September 1982) Chiariello M, Brevetti G, Genovese A, Cataffo A, Ambrosio G, Condorelli M. Dilazep-induced reduction of ischemic necrosis in rats with coronary artery occlu- sion. Int J Cardiol 1983; 2: 339-345. To zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA assess whether dilazep reduces myocardial necrosis we assigned 72 rats that survived coronary artery occlusion to 3 groups. The first zyxwvutsrqponmlkjihgfedcbaZYXWVU COntd group (n = 26) received coronary occlusion and was untreated. The second group (n = 21) received coronary occlusion and was treated with dilazep (150 pg/kg s.c.) every 8 hours for 48 hours. The third group (n = 25) was sham-operated. Forty-eight hours later the creatine-kinase activity of the left ventricle was measured. The calculated left ventric- ular fraction that survived the occlusion was larger in dilazeptreated rats (44.5 + 4.1% of left ventricle) than in controls (31.2 f 3.2%; zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJ P < 0.05). Twenty-six more rats also underwent coronary occlusion; 12 were controls and the remaining 14 were treated with dilazep at the same time and dose as before and killed 21 days after occlusion. Infarct size was evaluated on histological sections of the hearts by planimetry. The amount of left ventricle preserved from necrosis was larger in dilazep-treated rats, 82.1 + 0.9%, compared to controls 69.5 f 1.4% (P -c 0.05). Dilazep seems effective in preserving myocardial tissue from ischemic necrosis, and its beneficial effects are long-lasting, producing permanent reduction of infarct size. Introduction The evolution of an acute infarction can be favorably influenced by interventions that improve the balance between oxygen supply and demand either by increasing Reprint requests and correspondence to: Massimo Chiariello, M.D., Istituto di Patologia Medica, II FacoltL di Medicina, Via S. Pansini, 5, 80131-Napoli, Italy. 0167-5273/83/ooOO-0000/$03.00 0 1983 Elsevier Biomedical Press