THE RELATIVE BIOAVAILABILITY OF SELENIUM IN ZIYANG HIGH-Se WHEAT TO SELENIUM-DEFICIENT RATS / 营养学报

ABSTRACT

A three-phase depletion/repletion/depletion feeding study was designed to investigate the changes of Se levels and glutathione peroxidase (GSH-Px) activities in tissues and blood in rats fed for 6 weeks low-Se diet (6 ppb Se) from a Keshan disease area during the supplementations of Se as Ziyang high-Se wheat (1.175 ppm Se) or sodium selenite (dietary Se 219 and 223 ppb respectively) and after the supplements were discontinued, and to evaluate the relative bioavailability of Se in the wheat. The resalts showed that the average bioavailability of Se in high-Se wheat derived from the values at wk 2, 4 and 6 of supplement was close to that in selenite when plasma, erythrocyte, kidney, liver and cardiac Se contents were used as the response criteria, the relative bioavailabilities being 98%, 104%,100%,96% and 101% (sodium selenite = 100%) respectively. The bioavailability was lower for Se in high-Se wheat (70% or 90%) than for selenite when estimated by erythro-cyte or cardiac GSH-Px activities. However, the bioavailabilities of high-Se wheat Se in various tissues were not all the same at different stages of supplement. In addition, the effect of Se in high-Se wheat in maintaining either Se levels in heart, liver and erythrocyte or GSH-Px activity in heart was superior to that of selenite 3 weeks after the Se supplements were withdrawn.