1. Men with a genetic predisposition to essential hypertension had a significantly higher blood pressure during salt restriction and a greater elevation of blood pressure in response to salt loading than men without such a genetic predisposition.
2. The activity of platelet aggregation was significantly greater in men with a genetic predisposition to essential hypertension.
3. Platelet aggregation was activated directly or indirectly by an increased sodium intake.
4. This activation by an increased sodium intake was more pronounced in men predisposed to essential hypertension.