ESPINOZA, J.*; HUGGINS, T.; CATAPANE, E.J.; CARROLL, M.A.; Medgar Evers College, Brooklyn, NY; Medgar Evers College, Brooklyn, NY; Medgar Evers College, Brooklyn, NY; Medgar Evers College, Brooklyn, NY: Effects of Copper on Mitochondrial O2 Consumption and Cytochrome c Oxidase of the American Oyster, Crassostrea virginica
Our ongoing oyster rehabitation study is showing that Crassostrea virginica transplanted to Jamaica Bay, NY accumulate copper. Copper, a required trace metal in most cell systems, has prooxidant effects when present in excess. Mitochondria are sensitive to increased oxidative stress caused by metal toxicity. We studied the effects of copper on 02 utilization in oyster gill mitochondria from animals incubated 1-2 days with 0 to 100 ppb copper. Respiratory rates were monitored using a YSI Biological Oxygen Monitor. Once a baseline rate of consumption was determined, CuSO4 was added to the respiratory chamber to determine its acute effects. Adding 5 or 50 mg of CuSO4 to controls decreased respiratory rates by 12 and 32%, respectively. Copper exposed animals were significantly more sensitive to additions of copper with decreases of O2 utilization in excess of 34% with the 5 mg copper additions and an almost complete inhibition with 50 mg additions, showing copper had a deleterious effect on mitochondrial O2 utilization in vitro and that short term exposure of oysters in the lab to copper heightens this deleterious effect. We continued by examining effects of copper on 02 consumption and a component of the respiratory chain, cytochrome c oxidase, of 3 year old oysters which had been transplanted to Jamaica Bay. We found in vitro copper additions decreased O2 consumption as well as cytochrome c oxidase activity. This could be of physiological significance to the growth and health of oysters in waters of high copper content. The work was supported by grants 1R25GM62003 of NIGMS, 0516041071 of NYSDOE, the CUNY Groundworks Program, and 66288-0035 of PSC-CUNY. We thank Frank M. Flower & Sons, Inc., Oyster Bay, NY for supplying oysters.
