Effects of alinidine on survival and infarct size in rats with coronary artery occlusion.

Ligation of the left anterior descending coronary artery was performed in open-chest anaesthetized rats. One group had coronary occlusion for 3 h while ligation lasted for 30 min in a second group and was followed by a 150-min reperfusion period. The area at risk and area of infarction were determined immediately after premature death or 3 h after the ligature was set, by means of Evans blue and triphenyltetrazoliumchloride staining and subsequent photometric quantification. Saline or alinidine (5 mg/kg i.v.) was administered 15 min prior to ligation. The alinidine groups received a further 0.5 mg/kg i.v. 1 and 2 h after ligation. A large number of animals in the control groups died during the first 30 min. The animals that survived 3 h had a smaller area at risk than those dying prematurely and about 100% of the area at risk became infarcted. All animals in the two alinidine groups survived the first 30 min. All these animals survived with a larger area at risk than the control groups. The area of infarction in relation to the area at risk was significantly smaller than in the control groups. The cardioprotective effects of alinidine may be explained by a reduction in heart rate and a slight reduction in blood pressure.