Effects of azinphos-methyl on cellular immune responses of the freshwater snail Chilina gibbosa

CASTRO J; BIANCHI V; HERBERT LT; VENTURINO A; KRISTOFF G; LUQUET C

Buenos Aires

Congreso; 11th Biennial Meeting Society of Environmental Toxicology and Chemistry (SETAC) Latin America; 2015

SETAC LA

Agriculture is one ofthe main economical activities in Upper Valley of Río Negro and Río Neuquén inArgentina. The use of pesticides released during these activities maynegatively affect physiological responses of non-target exposed organisms. Arecent study has shown cholinesterase activity inhibition and neurotoxiceffects upon azinphos-methyl (AZM) exposure in Chilina gibbosa.Nevertheless, possible effects of this pesticide on the immune response havenot been studied yet in this species. The aim of this work is to characterizethe cellular immune response of C. gibbosa upon short-term exposure (48h) to environmentally relevant concentrations of AZM. To achieve this, snailswere collected from a site with no agrochemical pollution, and acclimated inlaboratory. The following treatments were set without aeration or feeding: 1)Control, 2) Solvent control (acetone) and 3) AZM 20 µg/L, (n = 6, each onecorresponding to pooled samples of hemolymph extracted from 3 snails,independently treated). Data were compared by one-way ANOVA and post hoccomparisons. Results: Total hemocyte number showed no variation betweentreatments. Cellular viability significantly decreased upon solvent exposure,but this effect was greater when snails were exposed to AZM. Relativeproportions of hyalocytes and round cells showed no variation betweentreatments; however, round cells were significantly more abundant thanhyalocytes, in general. Granulocytes were not observed in any sample. Phagocytosiswas mainly carried out by hyalocytes and was not affected by exposure to thesolvent, but was significantly inhibited by AZM, related to the control.Conclusion: Short-term exposure to AZM negatively affects cell viability andphagocytic activity in hemocytes of C. gibbosa, producing no changes inthe cellular type proportion.