Dahl salt-sensitive rats and human essential hypertension.

At Brookhaven we have two new strains of rats with opposing genetic predispositions to hypertension: one strain [inbred Dahl salt-sensitive (Dahl-S)] develops severe hypertension on a high-salt diet, while the other [inbred Dahl salt-resistant (Dahl-R)] responds only mildly, if at all. The striking observation is that, unlike other salt-sensitive hypertension-prone rats, inbred Dahl-S rats remain normotensive on a low-salt diet. The observation that hypertension in the inbred Dahl-S, but not the inbred Dahl-R, rat develops only after exposure to a high-salt diet indicates that the development of hypertension in the inbred Dahl-S strain is not spontaneous and that the genetic substrate is a critical determinant of the hazard of excess salt in the diet.