A new locus on chromosome 3 strongly linked with salt-sensitive high blood pressure in female F2 from SHRSP and WKY rats

Blood pressure QTL that differentiate Dahl salt-sensitive and spontaneously hypertensive rats

Our purpose was to define quantitative trait loci (QTL) for blood pressure that differ between two widely used hypertensive rat strains, the Dahl salt-sensitive (S) rat and the spontaneously hypertensive rat (SHR). A genome scan was done on an F(2) (S x SHR) population fed 8% NaCl for 4 wk. Three blood pressure QTL were detected, one on each of rat chromosomes (chr) 3, 8, and 9. For the chr 3 QTL the SHR allele increased blood pressure, and for chr 8 and 9 the S allele increased blood pressure. The QTL on chr 9 was exceptionally strong, having a LOD score of 7.3 and accounting for 30% of the phenotypic variance and a difference of 40 mmHg between homozygotes. A review of the literature in conjunction with the present data suggests that S and SHR are not different for the previously described prominent blood pressure QTL on chr 1, 2, 10, and 13. QTL for body weight on chr 4, 12, 18, and 20, each with an effect of about 30 g, were incidentally observed.

Cosegregation of the new region on chromosome 3 with salt-induced hypertension in female F2 progeny from stroke-prone spontaneously hypertensive and Wistar-Kyoto rats

1. We investigated candidate loci for salt-sensitive high blood pressure (BP) in F2 progeny from crossing Wistar-Kyoto and stroke-prone spontaneously hypertensive rats. 2. In female F2 progeny, systolic and diastolic BP on the 12th day and the seventh month after salt loading was strongly linked with the D3Mgh12 and D3Mgh6 loci on chromosome 3, respectively. 3. These loci were linked with BP only in female F2 progeny, not in males. 4. These results indicate that hormonal factors may influence salt sensitivity, particularly with respect to gender differences.