Genetic model of myocardial hypertrophy without elevated blood pressure in rats

Abstract

A population of fourth-, fifth-, and sixth-generation hybrids obtained by crossing SI IR and WKY rats was studied. These hybrids were a basis for obtaining a genetic model of myocardial hypertrophy (МH) without elevated blood pressure (BP). To reveal the given phenotype (MH without elevated BP), the degree of MH was noninvasively estimated by vectorocardiography in combination with noninvasive BP measurement on the caudal artery. Systolic BP in male hybrids of die fourth and fifth generation was 127 ± 3 and 123 ± 3 mm Hg, respectively, which was much lower than that in male rats of the progenitor line SHR (183 ±5 mm Hg) and practically equal to that in rats of the progenitor line WKY (128 ± 3 mm Hg). The similar BP values were also observed in female rats of the study populations. The weight of the heart of male hybrids F4. F5, and F6 was more than that in the WKY group (1,17 ± 0,03, 1,01 ± 0,04, and 1,19 ± 0,03 g, respectively, and 0,89 ± 0303 g, at p < 0,05 in WKY rats), but less than the values for the SHR group (1,38 ± 0,11 g, p < 0,05). The experimental model may be interesting and useful in solving a variety of physiological, genetic, and pharmacological problems.