The role of digestion in the black sea bass, Centropristis Striata, on the chemical speciation of organically bound cadmium

Abstract

1. The process of digestion ( in vivo and in vitro) upon the chemical form of intrinsic cadmium (Cd) in oysters was examined. 2. Analyses of stomach contents of adult black sea bass ( Centropristis strial), 6 hr after consuming oysters previously exposed to Cd, indicated that Cd was associated with five protein fractions having approximate molecular weights of > 160,000, 74,000, 38,000, 11,000 and <4000. 3. After 24 hr of in vivo digestion, analyses of intestinal contents indicated that most of the detectable Cd was associated with smaller molecular weight compounds. 4. Similar results were obtained in an in vitro digestion system; the Cd was associated with somewhat larger complexes than those found in the in vivo digestion. 5. Free amino acids were present in the low-molecular weight organo-Cd fraction, suggesting a possible role of amino acids in intestinal Cd transport.