Heart/body weight ratios for aging high and low blood pressure mice

Heart weight and heart/body weight ratios were determined for stocks of mice bred from Schlager's high and low blood pressure mice. Results of an analysis in which three different age groups (means = 15, 17, and 28 months) were compared indicated a nonsignificant interaction between age and blood pressure for heart weight and between age and blood pressure for heart/body weight ratios. Heart weight and heart/body weight ratios were significantly higher for the high than for the low BP mice at all ages with one exception; heart weights did not differ between the two lines at mean age 28 months. It was concluded that high blood pressure mice do not exhibit cardiac hypertrophy in the strictest sense of a disproportionately greater increase in heart/body weight ratios across the life span than low blood pressure for this particular stock.