Meeting Abstract
P2.103 Jan. 5 Effect of Heavy Metals on Glutathione S-Transferase Activity in Digestive Gland of the American Oyster, Crassostrea virginica WILTSIE, Kenya*; CARROLL, Margaret A.; CATAPANE, Edward J; Medgar Evers College; Medgar Evers College; Medgar Evers College margie@mec.cuny.edu
The New York harbor area, including Jamaica Bay (JB) contain metal and organic pollutants in levels higher than NYS Water Quality Standards. Bivalve mollusks are often utilized for metal monitoring and bioaccumulation kinetics studies but little is known about their biochemical responses to metal accumulations. Metal accumulations increase oxidative stress by various means including depletion of cellular antioxidants such as the thiol glutathione (GSH). Glutathione S-transferases (GSTs) are a group of Phase II detoxification enzymes that utilize GSH to conjugate electrophilic substrates. While extensive research was done on GST in mammals less is known about it in oysters and invertebrates in general. In this study GST activity of the post-mitochondrial fraction of C. virginica digestive gland was determined in the presence of acute additions of various heavy metals (65-800 µM) including silver, lead, cadmium, copper, mercury and iron. GST activity was measured spectrophotometrically using CDNB and GSH as substrates and the enzyme’s specific activity was calculated using the conjugate’s molar extinction coefficient. We found each metal except iron decreased GST activity. We further studied effects of a 2 day in vivo incubation of oysters with cadmium (up to 600 µM). The results show the 2 day treatments had no significant effects on digestive gland GST activity suggesting the whole intact animal may be able to protect against the short term insult of cadmium. Understanding toxicological effects of metal pollutants on C. virginica will assist federal and local regulators in making informed environmental decisions that protect aquatic ecosystems, improve water quality of the New York harbor area, and advance restoration efforts in JB and other areas.
