Rat models of cardiac disease
By Richard Row
Cardiovascular disease is the most frequent cause of death worldwide at over 17 million deaths per year – over 30% of all deaths. Coronary heart disease alone kills more than 7 million people every year. Where available, proactive health care measures such as risk factor screening, behavior modification, and prophylactic drugs greatly reduce this burden. All of these treatments were developed based on a tremendous volume of research in which animal models played a crucial role. In particular, rat models of heart disease have enabled tremendous advances in human health.
Premiere animal model of human heart disease
Rats became the premiere animal model for human heart disease thanks in large part to new surgical techniques developed in the 1950s. Researchers needed to study animals that had damaged heart tissues but this damage couldn’t be introduced in a reliable or reproducible manner. Because larger animals such as dogs were commonly used the cost of progress was unacceptably high. The hearts of smaller animals have physiological differences from a human’s but the costs of using them for research are much lower. To identify the best model researchers at the National Institutes of Health tested a procedure for damaging heart tissues in mice, rats, hamsters and guinea pigs. The simple surgical technique was found to work best in rat models and the method was widely adopted by the research community. This technique complemented a strain of hypertensive rats developed in Japan around the same time. Such models became the foundation of the modern era of research into the prevention and treatment of heart disease. In more recent years mice gained prominence as models for human heart disease because targeted genetic modifications could be introduced. Now the rat genome can be modified almost as freely as in the mouse with the new technique of gene editing in spermatagonial stem cells. This expansion of research possibilities should create a renaissance for the rat as a model for human heart disease.
Experimental Myocardial Infarction: I. A Method of Coronary Occlusion in Small Animals. T. N. P. Johns and B. J. Olson. Annals of Surgery (1954)