Abstract
A previously described pst I restriction fragment length polymorphism in Dahl rats at the Na+, K+-adenosine 5'-triphosphatase (ATPase) α1 isoform locus was tested for cosegregation with blood pressure in segregating populations. Inbred Dahl salt-sensitive (S) and inbred Dahl salt-resistant (R) rats were crossed to produce F1 rats, and three segregating populations, F1 x R, F2 and F1 x S, were produced and raised on a high-salt diet for variable periods to attain the maximal blood pressure response in each population. In no segregating population was there a significant difference in blood pressure among genotypes at the Na+, K+ -ATPase α1 locus. Power calculations suggest that single-allele dosage effects of +, K + -ATPase α1 locus do not influence blood pressure under the conditions of these experiments (high dietary salt, Dahl rat genetic background) or, if they do, their effect is small.