The use of spontaneously hypertensive rats for the study of anti-hypertensive agents

Hypertension studies using laboratory animals have been conducted since 1930. These were not completely satisfactory because either surgery or pharmacologic induction were required to produce hypertensive animals. Many attempts have been made to breed spontaneously hypertensive rats, mainly from the Okamoto strain. The cause of hypertension in the rat, with specific reference to genetic aspects and pathogenicity, were reviewed. The hypertensive rat is an acceptable model for hypertension studies because of the stability of the hypertensive state and the reproducibility of experimental effects. It is a particularly useful model for screening antihypertensive agents. Development of mutant Okamato stran rats which have brain softening, cerebral hemorrhages, and myocardial infarctions would permit the screening of specific therapeutic agents with fewer side-effects. Mutants which develop obesity, hyperlipidism, and early atherosclerosis have been reported in Okamoto strain X Sprague-Dawley rat crosses.