Differential in vitro effects of some pesticides on carbonic anhydrase activities from some freshwater and seawater fish erythrocytes

Abstract

The purpose of this study was to investigate the in vitro effects of 4 commonly used pesticides: the fungicides Nuarimol(TM) [alpha-(2-chlorophenyl)-alpha-(4-fluorophenyl)-5-pyridinemethanol] and Fenarimol(TM) [alpha-(2-chlorophenyl)-alpha-(4-chlorophenyl)-5-pyridinemethanol], the insecticide Parathion-methyl(TM) [0,O-dimethyl-O-(4-nitrophenyl) phosphorothioate] and the herbicide 2,4-D(TM) [2,4-dichlorophenoxy acetic acid, ammonium salt] on erythrocyte carbonic anhydrases (CA) activity from Cyprinus carpio, Scorpaena porcus, Diplodus vulgaris, Salmo gairdnerii and Barbus barbus. Erythrocyte CA enzymes from different fish species were purified by using Sepharose-4B-L-tyrosine-sulphonamide affinity gel. I-50 values of the chemicals that caused inhibition were determined by means of activity percentage [I-50] diagrams. The pesticides used in this study inhibited the CA activity from different fish species to various degrees. It was found that Nuarimol(TM) and Fenarimol(TM) were the most potent inhibitors for all fish species, ranging from 0.18mM to 0.59MM, whereas the others, Parathion-methyl(TM) and 2,4-D(TM), exhibited relatively low inhibitory effect with I-50 values ranging from 1.26mM and 3.19mM for Cyprinus carpio, Barbus barbus, Salmo gairdnerii and Diplodus vulgaris. The comparison of the I-50 values of these fish species indicates a higher carbonic anhydrase sensitivity for Scorpaena porcus to all pesticides. The concentrations of Nuarimol(TM), Fenarimol(TM), Parathion-methyl(TM) and 2,4-D(TM) that inhibited in vitro 50% of enzymatic activity (I-50) Of Scorpaena CA were 0.2mM, 0.18mM, 0.62mM and 0.68mM, respectively.