PLASMA AND LIVER SELENIUM LEVELS IN THE RAT DURING SUPPLEMENTATION WITH 0.5, 2, 6, AND 15 PPM SELENIUM IN DRINKING-WATER

Plasma and liver selenium of Wistar rats were determined after 1, 3, a nd 6 mo supplementation with 0.5, 2, 6, or 15 ppm selenium as sodium s elenite in drinking water. Plasma selenium was not different from cont rol values at additional intake of 0.5 ppm but increased above usual l evels at higher intakes. A highly significant correlation was observed between the total quantity of selenium ingested and plasma selenium a fter 1 mo treatment (r = 0.99, p < 0.01), but was less pronounced afte r 3 and 6 mo (0.94, p < 0.05, and 0.78, p < 0.05, respectively). The d ecrease in plasma selenium with time of treatment was more pronounced at higher intakes. There was also a highly significant correlation bet ween total selenium intake and liver selenium concentration (r = 0.99, p < 0.01) after 1 mo of treatment, but this time liver selenium did n ot change with time, and the correlation remained highly significant t hroughout the investigation. Liver selenium therefore appears as a mor e sensitive and more representative measure of selenium intake than pl asma selenium. Most supplements did not affect body weight and surviva l of animals, except when the diet was supplemented with 15 ppm for 6 mo; however, alterations in biochemical parameters concerning lipid st atus and hepatic function were observed at levels above 2.0 ppm.