Tissue distribution of mercury and selenium in minnows, Phoxinus phoxinus

Abstract

The protective effect of selenium against mercury toxicity has been extensively demonstrated in a number of studies (Burke eta]. 1977; Kasuya 1976). Since mercury uptake is not always diminished by the presence of selenium (Kim eta]. 1977) and neither does selenium enhance the elimination of mercury (Lucu and Skreblin i981; Cuvin and Furness 1988), these findings indicate that the mechanism for the observed protective action of selenium against mercury toxicity lie along different lines. It is believed that the rechanelling of mercury from one organ or tissue to another is one of the general mechanisms involved in the protective action of selenium against mercury toxicity. This is supported by the fact that one of the observed effects of selenium treatment on mercury-intoxicated animals is the apparent modification of the distribution pattern of mercury in the different organs and tissues. Decreased mercury levels in the kidney after selenium treatment has been demonstrated in rats by Chen eta]. (1974) and Potter and Matrone (1974).

The following study aims to determine the effect of selenium on the distribution pattern of mercury in a common freshwater fish, the minnow Phoxinus phoxinus (Order Cypriniformes; Family Cyprinidae). Conversely, the effect of mercury on the tissue distribution of selenium will also be studied.