In vivo and in vitro acetylcholinesterase inhibition by metacid-50 and carbaryl in Channa punctatus under natural field condition.
Channa punctatus (Bloch), cultivated under paddy-cum-fish culture programs, was exposed to non-lethal levels of 0.239 ppb of Metacid-50 and 3.73 ppm of Carbaryl for 7 days in the field. These insecticides effected significant inhibition of brain acetylcholinesterase (AChE) activity accompanied by a concurrent increase in acetylcholine (ACh). In vitro inhibition of brain acetylcholinesterase was also compared between unexposed and pesticide exposed fish. Data revealed that the time taken for 50% inhibition (t0.5) of the enzyme was less in the pesticide exposed fish as compared to that of the unexposed fish. This indicates a preformed effect of the test pesticides on fish brain AChE during the in vivo exposure while the in vitro effect is an additive inhibition of the enzyme caused by the circulating inhibitors reducing the t0.5. Acetylcholinesterase inhibition may thus be utilized to monitor pesticide pollution in agricultural fields.
Ghosh
P
P
Department of Zoology, Visva-Bharati University, Santiniketan, India.
Bhattacharya
S
S
D000109:Acetylcholine / Q000378:metabolism; D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000201:enzymology; D012721:Carbaryl / Q000633:toxicity*; D002800:Cholinesterase Inhibitors; D004784:Environmental Monitoring; D005399:Fishes; D007306:Insecticides / Q000633:toxicity*; D008743:Methyl Parathion / Q000633:toxicity*
D002800:Cholinesterase Inhibitors; D007306:Insecticides; D008743:Methyl Parathion; D000110:Acetylcholinesterase; D000109:Acetylcholine; D012721:Carbaryl