Development of a Strain of Spontaneously Hypertensive Rats

Abstract

A male rat with spontaneously high systolic blood pressures of 150 to 175 mmHg persisting for more than one month and a female rat with blood pressures slighty above the average, 130 to 140 mmHg, were selected from among 68 Wistar strain rats in normal condition and mated to obtain F1 rats. Of these F1 rats, males and females with hypertension (blood pressure exceeding 150 mmHg) persisting for more than a month (mostly over 2 months) were mated to produce F2 rats. The procedure was repeated to obtain F3, F4, F5 and F6 rats totaliag 380 animals. The weights and blood pressures (by the tail-water-plethysmographic method) were measured once weekly biginning at 4 weeks of age, and the results can be summarized as follows : 1. In body weight, the F rats showed little difference from the normal