Further evidence for genetic independence of blood pressure and salt appetite in spontaneously hypertensive and Wistar-Kyoto rats.

We previously reported that blood pressure and volitional consumption of salt were under independent genetic regulation in the F2 population of crosses between Spontaneously Hypertensive (SHR) and Wistar-Kyoto (WKY) rats. However, the use of 1.5% NaCl as the test solution in that study might have resulted in a limit on the range of variability in saline consumption that could possibly have obscured a correlation between these traits, if one existed. In the present study, volitional consumption of normal (.9%) saline and blood pressure were measured in a sample of 61 adult male F2 (SHR x WKY) rats. There was considerable inter-individual variance in saline consumption (2 to 100 ml/day), indicating that the range of intake was not truncated in this experiment. However, there was no correlation between blood pressure and any measure of saline consumption in the F2 sample, again indicating that ad libitum salt appetite and blood pressure are genetically independent in the SHR and WKY strains of rats.