In vitro exposure of heavy metals on nucleotidase and cholinesterase activities from the digestive gland of Helix aspersa.

Zinc, copper and cadmium are important environmental contaminants and differences in purinergic and cholinergic systems of invertebrates have been described when compared to characteristics of these signaling systems in vertebrates. Here we evaluate the effect in vitro of these metals on the ATPase, 5'-nucleotidase and cholinesterase (ChE) activities in the digestive gland of Helix aspersa. Zinc (500 and 1000 microM) promoted a significant decrease in 5'-nucleotidase activity.