EFFECT OF DIETARY PHYTOSTEROLS ON RAT-TISSUE LIPIDS

The present study was designed to examine the incorporation of phytost erols (PS) in membranes and tissues of rats fed a diet containing 2% P S in the presence of 0.2% cholic acid for 22 days. The control diet co ntained 12 mg PS/100 g compared with 2,012 mg/100 g. Liver, kidney, te stis, and prostate microsomes, plasma, and epididymal fat pads were ex amined for sterols. Fatty acid composition and phospholipid pattern we re also examined in some tissues. The PS diet resulted in a fivefold i ncrease in plasma PS compared with controls. PS was found to accumulat e in adipose tissue and liver microsomes in rats fed the PS-supplement ed diet. There was no effect of PS incorporation on microsomal cholest erol content, except in the testes, in which dietary PS reduced choles terol content by 25%. Dietary PS increased 20:4n-6 and 22:5n-3 fatty a cids in membranes of the liver, testis, and prostate but decreased 16: 1 in liver microsomes. PS incorporation had no effect on the phospholi pid pattern of the liver and testis.