Mechanisms and functional morphology associated with metal transport in Mercenaria mercenaria (bivalvia: mollusca): Progress report No. 7 for the contract period 1 September 1985 to 31 December 1986

Studies on metal transport in the quahog, Mercenaria mercenaria, are reported. Podocytes, a specialized type of cell that functions in ultrafiltration, have been identified in the pericardial glands of the quahog using transmission and scanning electron microscopy raising the question of whether metals may reach the kidney via the primary urine, or whether most metals arrive in the kidney via the blood. The accumulation of /sup 109/Cd in quahog extracellular kidney granules suggests the involvement the kidney cell's lysosomal system in the overall process of metal sequestration. The different patterns of metal interactions observed in the quahog kidney, digestive gland and gill demonstrate that each of these three organs utilizes different mechanisms of metal detoxification and accumulation.