ملخص: ObjectivesTo investigate the effect of two types of dietary protein on blood pressure, liver fatty acid desaturation and composition, and urine 6-keto-prostaglandin-F (PGF1[alpha]) level, the metabolite of prostacyclin.Methods5-wk-old spontaneously hypertensive rats were fed 20% casein or purified fish protein. The fat source was 5% ISIO oil, which contains 47.9% ([omega]-6) and 1.7% ([omega]-3) total polyunsaturated fatty acids. After 2 mo on the diet, systolic blood pressure was reduced with fish protein compared with casein (189.8 +/- 10.5 versus 220.7 +/- 8.7).ResultsExcretion of 6-keto-PGF1[alpha] in urine was negatively correlated with blood pressure. Liver cholesterol and phospholipid concentrations were 1.71- and 1.27-fold lower with fish protein than with casein, respectively. The fish protein diet lowered the 20:4([omega]-6) proportion and the ratio of 20:4([omega]-6) to 18:2([omega]-6) in liver microsomal lipids and phospholipids, which was due to the reduced microsomal [Delta]6([omega]-6) desaturation activity. Dietary protein source did not affect [omega]-3 fatty acid composition, and this was associated with a similar activation of [Delta]6([omega]-3) desaturation in liver microsomes.ConclusionsThe present data indicated a significant blood pressure-lowering effect caused by fish protein, rather than by casein, that modified the fatty acid composition of liver phospholipids and liver microsomal total lipids.

لغة: إنجليزية