Dietary sodium and renal alpha 2-adrenergic receptors in Dahl hypertensive rats

Dahl sodium-sensitive and resistant rats were fed low and high sodium diets. Renal plasma membrane alpha 2-adrenergic receptor concentrations were greater (p less than .05) in sensitive than in resistant rats while ingesting a low sodium diet. On a high sodium diet the alpha 2 receptor concentration increased (p less than .01) in sensitive but not in resistant rats. Since alpha 2 receptors are located in proximal tubules at sites where norepinephrine induces sodium reabsorption, we postulate that this genetically determined abnormal receptor regulation could lead to exaggerated sodium retention and possibly high blood pressure.