Acute and chronic effects of cadmium on blood homeostasis of an estuarine crab, Chasmagnathus granulata, and the modifying effect of salinity

RODRÍGUEZ, E.M.; BIGI, R.; MEDESANI, D.A.; STELLA, V.S.; LÓPEZ, L.; RODRÍGUEZ MORENO, P.A.; MONSERRAT, J.M.; PELLERANO, G.N.; ANSALDO, M.

BRAZILIAN JOURNAL OF MEDICAL AND BIOLOGICAL RESEARCH

ASSOC BRAS DIVULG CIENTIFICA

Año: 2001 vol. 34 p. 509 - 518

0100-879X

Whole body oxygen consumption and some hemolymphatic parameters such as pH, partial pressure of gases, level of ions and lactate were measured in the estuarine crab Chasmagnathus granulata after both an acute (96 h) and chronic (2 wk) exposure to cadmium at concentrations ranging from 0.4 to 6.3 mg/l. In all instances, the crabs developed hemolymphatic acidosis, but no respiratory  (increased PCO2) or lactate increases were evident. Hemolymphatic levels of sodium and calcium were always increased by cadmium exposure. The chronic toxicity of cadmium was enhanced at 12 ‰ salinity, even causing a significant 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 the oxygen consumption and PCO2, an increase of PO2, along with no changes in lactate levels. These imbalances were associated to severe necrosis and telangectasia in the respiratory gills, probably leading to respiratory impairment and finally histoxic hipoxia and death of the animals.