Effects of environmental concentrations of atrazine on hemocyte density and phagocytic activity in the pond snail Lymnaea stagnalis (Gastropoda, Pulmonata).
Immunotoxicological effects of environmentally relevant concentrations (10, 23, 50, 100 microg/l) of atrazine were studied in Lymnaea stagnalis. Individual hemolymph sampling was performed at 0, 24, 48, 72, 96, 168, 336, 504 and 672 h during exposure. Every atrazine concentration induced a significant increase in the mean number of circulating hemocytes, without any concentration-response relation. A peak (1.6-fold increase) of hemocyte density was observed after 96 h of exposure. After 504 h, the number of hemocytes remained higher only in the snails exposed to the two highest concentrations. Granulocytes contributed most to the increase in hemocyte density in herbicide-exposed snails. Both short- (24 and 96 h) and long-term (504 h) exposures resulted in significant inhibition of hemocyte phagocytic activity upon E. coli. Over the long-term, phagocytosis recovered for the two lowest concentrations. After 504 h of exposure, every herbicide level resulted in a significant reduction of reactive oxygen species production in E. coli-stimulated hemocytes, which was not observed for short-term exposures.
UMR 6553 Ecobio CNRS Université de Rennes 1, Campus de Beaulieu, F-35042 Rennes cedex, France. jacqueline.russo@univ-rennes1.fr
Jacqueline
J
Russo
Laurent
L
Lagadic
D000818:Animals; D001280:Atrazine / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000276:immunology; D006434:Hemocytes / Q000187:drug effects / Q000502:physiology; D008195:Lymnaea / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D010573:Pesticide Residues / Q000633:toxicity*; D010587:Phagocytosis / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D016897:Respiratory Burst / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D010573:Pesticide Residues; D017382:Reactive Oxygen Species; D014874:Water Pollutants, Chemical; D001280:Atrazine