Influence of linoleic acid in the diet on arterial pressure of salt loaded rats. II. Effects on plasma catecholamine concentration, renin activity, and reactivity of isolated vessels.

1. A linoleic acid free diet and indomethacin treatment induce an increase in the epinephrine and norepinephrine concentrations in the plasma. 2. The renin activities in the kidney and plasma were increased by a linoleic acid free diet and decreased by indomethacin treatment. 3. The reactivity of isolated blood vessels to norepinephrine, angiotensin, PGE2 and PGA2 was intensified after linoleic acid free diet. Indomethacin treatment neutralized the differences between the different diet groups. We conclude that the increase in the sympathetic activity, in the renin activity and in the vasoreactivity after a linoleic acid free diet has promoted the elevation of blood pressure of salt loaded rats and that these prohypertensive changes have been caused by a diminished PG biosynthesis in kidneys and blood vessels.