Turnover of Dietary Cholesterol and β-Sitosterol in the Prawn

Abstract

The fate and turnover of cholesterol and β-sitosterol in the prawn Penaeus japonicus were investigated after the feeding of [4-14C] cholesterol and [22, 23-³H] β-sitosterol. Lipids were ex-tracted from the gut, hepatopancreas, hemolymph, muscle, and the remainder for analysis after 1, 24, and 240 hs of feeding of radioactive sterols. In the whole body, the half-lives (T_1/2) of cholesterol and β-sitosterol were 5.4 days and 2.8 days, respectively. Cholesterol (T_1/2=2.4 days) turned over at a faster rate in the hepatopancreas than β-sitosterol (T_1/2=5.7 days), whereas cholesterol (T_1/2=12.2 days) was retained in the muscle for a longer tiem than β-sitosterol (T_1/2= 5.9 days). The prawn possessed the ability for conversion of β-sitosterol to cholesterol probably via 24-ethylidenecholest-5-enol and 24-methylenecholesterol. Ten days after feeding [³H] β-sitosterol, the whole body of the prawn contained large amounts of radioactive cholesterol (43% of total radioactive sterols).