title: In vitro exposure of heavy metals on nucleotidase and cholinesterase activities from the digestive gland of Helix aspersa.
abstract: 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. However, it did not induce changes in ATP hydrolysis. Copper (25 and 50 microM), inhibited significantly ATPase activity, but did not alter 5'-nucleotidase when compared to control (no metal added). In relation to effects of cadmium, an inhibitory effect on ATP hydrolysis has been observed at concentrations of 100, 500 and 1000 microM and a similar decrease of AMP hydrolysis was observed at 500 and 1000 microM. However, there were no significant changes in ChE activity from homogenates of the digestive gland of H. aspersa for all metals tested. This study demonstrated that zinc, cadmium and copper affect ATPase and 5'-nucleotidase in digestive gland, but not ChE, suggesting that the purinergic system may be a target related to toxicity induced by these metals and a possible indicator of biological impact of exposure to these contaminants.
authors.affiliation: Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga, 6681, Porto Alegre, RS, Brazil.
authors.forename: Kelly Cristine
authors.initials: KC
authors.lastname: de Souza Dahm
authors.forename: Caroline
authors.initials: C
authors.lastname: Rückert
authors.forename: Elisa Marchezan
authors.initials: EM
authors.lastname: Tonial
authors.forename: Carla Denise
authors.initials: CD
authors.lastname: Bonan
mesh_terms: D015720:5'-Nucleotidase / Q000037:antagonists & inhibitors / Q000378:metabolism; D000249:Adenosine Monophosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D002802:Cholinesterases / Q000378:metabolism; D003300:Copper / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity; D041981:Gastrointestinal Tract / Q000187:drug effects* / Q000378:metabolism; D006372:Helix, Snails / Q000187:drug effects* / Q000378:metabolism; D015032:Zinc / Q000633:toxicity*
chemical_list: D004785:Environmental Pollutants; D002104:Cadmium; D000249:Adenosine Monophosphate; D003300:Copper; D002802:Cholinesterases; D015720:5'-Nucleotidase; D000251:Adenosine Triphosphatases; D015032:Zinc