Abstract
Dahl salt sensitive rats (DS) developed severe hypertension on four weeks of high salt feeding while the Dahl salt resistant rats (DR) remained normotensive under the same conditions. The specific maximal binding of epidermal growth factor (EGF) in the freshly prepared kidney membranes of high salt fed DS rats was higher than those from DR rats (5.3±1.9 vs. 1.6±0.62fmoles/mg protein, p<0.001). Scatchard analysis of EGF binding in the kidney showed one class of receptors in the DR (Kd=0.75±0.05 nM) as well as in the DS rats (Kd=0.69±0.06nM). The EGF binding in the aortic membranes of DS rats was also high compared to DR rats (24.98±5.52 vs). 13.20±4.10 (moles/mg protein, p< 0.001). Scatchard analysis of EGF binding in the aorta showed one class of receptors in the DR aorta with a Kd of 0.70±0.06nM. On the other hand, in the DS rat aorta two classes of receptors, a high affinity form (Kd=0.05±0.01nM) and a low affinity form (Kd=3.5±0.3nM) were noted. The induction of a high affinity species of EGF receptors in the aorta, appears to be a mechanism unique to the salt fed DS rats. (Hypertens Res 1996; 19: 65-68)
