Hydrolysis of carbohydrates in roach (Rutilus rutilus (L.)) at different levels of mercury accumulation

The effect of mercury accumulation on the intestinal glycosidase activity in perch Perca fluviatilis L. from aquatic bodies of European Russia with different pH

“…A study of the effect of the Hg contained in the feed of natural origin on the enzyme activities hydrolyzing proteins and carbohy drates in hydrobionts (fish, daphnia, and chironomid larvae) have demonstrated differently directed changes of this metal on the enzymes involved in the carbohydrase and protease chains in one and the same species, as well as the dependence of the value and direction of its effect on hydrobiont species and exper imental conditions [6]. The chronic experiments with young perch and roach Rutilus rutilus (L.) receiving feed with a background (0.02 mg per 1 kg fresh feed weight) and increased (0.3-0.4 mg/kg) Hg contents have demonstrated intensive Hg accumulation in the body of yearlings at a concentration comparable to the content of organomercury compounds added to pools [4,5]. An increased Hg content in muscles (0.05-0.16 mg/kg) in developing juvenile fish decreases the digestive glycosidase activities as well as the enzyme affinities for a substrate, thereby slowing down the rate of the initial digestion stages of the carbohydrate com ponents of food.…”