The breeding for development of myocardial infarction in WHHL rabbits

点击翻译按钮获取中文摘要

The Watanabe heritable hyperlipidemic (WHHL) rabbit shows hyperlipidemia from birth, owing to a genetical deficiency of the low density lipoprotein receptors. The aortic and coronary atheros-clerosis occur at a premature age in this animal. However, myocardial infarction does not develop often in the yound rabbits. We carried out selective breeding in an attempt to increase in the incidence of this lision in WHHL rabbits. In this study 88 rabbits after selective breeding (MI-line) sere compored with 93 rabbits before selective breeding (non MI-line) in order to estimate the breeding effect. The results were as follows : 1). The average of the percent of narrowing was 56% in non MI-line, 66% in F1 of MI-line, 77% in F3 of MI-line and 78% in F4 of MI-line. 2). The frequency of over 75% narrowing was 26% in non MI-line and increased to 41% in F1, 67% in F3 and 75% in F4 of MI-line. 3). The incidence in myocardial infarction was 13% in non MI-line and increased to 15% in F1, 26% in F3 and 25% in F4 of MI-line. 4). WHHL rabbits aged over 10 months in which myocardial infarction provoked were always observed over 75% narrowing in coronary arteries, whereas in the rabbits aged under 10 months there were no relation between myocardial infarction and the severe coronary narrowing. 5). The incidence of myocardial infarction in the male rabbits was significantly higher than that in the female. Consequently, we considered that both coronary narrowing and myocardial infarction were expanded because of the selective breeding.