Fish protein improves blood pressure but alters HDL2 and HDL3 composition and tissue lipoprotein lipase activities in spontaneously hypertensive rats.

The two-month effects of dietary fish protein and casein on VLDL, HDL(2) and HDL(3) compositions and hepatic lipase (HTGL) and tissue lipoprotein lipase (LPL) activities were examined in spontaneously hypertensive rats (SHR) at 4 wk of age. After 2 mo of experiment, the fish protein diet induced lower blood pressure (-14 %) as compared to casein. Liver triacylglycerol and total cholesterol concentrations were 1.37- and 1.71-fold lower in the fish protein group than in the casein group, respectively. Total cholesterol concentration in plasma was also diminished by fish protein (-21 %) and was reflected in HDL(2) fraction (-44 %). SHR fed the fish protein diet as compared with those fed casein, showed a significantly low HDL(3) particle number, as measured by diminished HDL(3) mass and apo A-I. The consumption of fish protein did not affect VLDL particle number, but significantly decreased VLDL-triacylglycerol (-32 %) and adipose tissue total lipid concentrations as compared to casein. This was accompanied by diminished HTGL and adipose tissue LPL activities (-10%, -91%, respectively). These data demonstrate that fish protein plays an antihypertensive role and reduces plasma and tissue lipid concentrations. Thus, a fish protein intake might be beneficial for patients with hypertension.