The Inheritance of Coronary Artery Anatomic Patterns in Rats

Coronary artery anatomic patterns were determined in 4,500 rats obtained from three unrelated inbred strains. Four basic patterns were defined based on the presence of one or two primary trunks arising from separate ostia on each side. The frequency distribution of these patterns was significantly different among the three strains. Breeding experiments showed that the patterns are polygenetically determined. Although the presence of asymmetrical patterns in each strain suggests independent determination of each side, some interaction between the factors determining the two sides was also demonstrated. These patterns may provide a model to test the hypothesis that such inherited differences in coronary patterns may be a factor in susceptibility or resistance to coronary atherogenesis and myocardial infarction.