ACUTE AND CHRONIC EFFECTS OF CADMIUM ON BLOOD HOMEOSTASIS OF AN ESTUARINE CRAB, CHASMAGNATHUS GRANULATA, AND THE MODIFYING EFFECT OF SALINITY

RODRIGUEZ, E.M., BIGI, R., MEDESANI, D.A.,STELLA, V.S., LÓPEZ GRECO, L.S., MORENO, P.A., MONSERRAT, J.M., PELLERANO, G. Y M. ANSALDO

BRAZILIAN JOURNAL OF MEDICAL AND BIOLOGICAL RESEARCH

Año: 2001 vol. 34 p. 509 - 518

0100-879X

Whole body oxygen consumption and some hemolymph parameters such as pH, partial pressure of gases, level de ions and lactate were measured in the estuarine crab Chasmagnathus granulata after both acute (96h) and chronic (2 weeks) exposure to cadmium at concentrations ranging from 0.4 to 6.3 mg/l. In all instances, the crabs developed hemolymph acidosis, but no respiratory (increased PC02) or lactate were evident. Hemolymph levels of sodium and calcium were always increased by cadmium exposure. The chronic toxicity of cadmium was enhanced at 12 ‰ salinity, even causing a significantly higher mortality in comparison with the higher salinity (30 ‰) used. A general metabolic arrest took place at 12  ‰ salinity in the crabs chronically exposed to cadmium, as indicated by decreases of oxygen consumption and PC02, in increase of PO2, along with no changes in lactate levels. These imbalances were associated with severe necrosis and telangiectasia in the respiratory gills, probably leading to respiratory impairment and finally histotoxic hypoxia and death of the animals.