Hamet P: Thermosensitivity, a possible new locus involved in genetic hypertension. Hypertension 1989;14:121-128

Spontaneously hypertensive mice have been characterized as more sensitive to environmental heat than normotensive mice. A breeding program was therefore initiated to examine the possible genetic link between thennosensitivity and hypertension. Crossbreeding of spontane-ously hypertensive mice with randomly bred normotensive mice produced F, hybrids, which were then intercrossed to create a F2 population. Thermosensitivity was measured with a noninvasive method. The rate of body temperature increase was significantly (p<0.001) higher in the hypertensive mice (1.74±0.04 ° C/min) compared with normal controls (1.13±0.03 ° C/ min). The frequency distribution of the rate of body temperature increase among the progenies was consistent with the hypothesis that a single gene locus determines the observed difference in thermosensitivity between normal and hypertensive mice. The allele that determines the rate of body temperature increase in normal mice was dominant in relation to the allele contributed by hypertensive mice. In the F2 population, a bimodal distribution determined two phenotypes: less than 1.40 ° C/min and greater than 1.40 ° C/min. A significant difference (p<0.0l) in blood pressure of 11 mm Hg was observed between these two phenotypes. In addition, a positive correlation (p<0.01) was noted between the rate of body temperature increase and bloo