Antihypertensive action of dietary polyunsaturated fatty acids in spontaneously hypertensive rats.

The experiments were carried out in order to clarify the mechanisms of attenuation of hypertension development by means of diets enriched with polyunsaturated fatty acids (PUFA) in spontaneously hypertensive rats (SHR). Female SHR were fed a linoleic acid rich (LAr) diet (13.3 cal % LA, sunflower oil), a linolenic acid rich (LNAr) diet (18.8 cal % LNA, 3.9 cal % LA; linseed oil) and a PUFA deficient diet (0.5 cal % LA, hydrogenated palm kernel fat), respectively, during the last week of pregnancy and during the suckling period. Corresponding diets were given to the male offspring up to an age of 16 weeks. Our results demonstrate that the attenuation of hypertension development in LAr and LNAr fed male SHR was paralleled by an increased in-vitro uptake of 14C-norepinephrine into cardiac and aortic tissues as well as an increased degradation rate of 14C-norepinephrine in cardiac tissue. Ex vivo prostaglandin (PG) formation was reduced after LNAr diet in the aorta (PGF2 alpha, PGI2-like material) and in the kidney medulla (PGE, PGF2 alpha). It is concluded that an increased catecholamine inactivation may play a role in the attenuation of hypertension development in LAr and LNAr diet fed SHR.