DIFFERENT SENSITIVITY TO ORGANOPHOSPHATES OF ACETYLCHOLINESTERASE AND BUTYRYLCHOLINESTERASE FROM THREE-SPINED STICKLEBACK (GASTEROSTEUS ACULEATUS): APPLICATION IN BIOMONITORING

摘要

Different cholinesterases from brain and body muscle of the fish three-spined stickleback (Gasterosteus aculeatus) were investigated concerning their potential use in the biomonitoring of organophosphate insecticides (OPs). Stickleback brain contained acetylcholinesterase (AChE) but no butyrylcholinesterase (BChE). Body muscle contained both AChE and BChE. In vitro, body muscle BChE was three orders of magnitude more sensitive than brain or body muscle AChE to the OPs paraoxon and dichlorvos. In l998, cholinesterase activities were recorded in stickleback from eight streams differing in pesticide contamination. Automated on-site samplers that selectively collect water during runoff events were used to obtain water samples for pesticide analysis. The OP parathion was found in stream water sampled during runoff events in five cases. The variation of brain and body muscle AChE activity between streams was not related to water contamination by pesticides. Body muscle BChE was strongly decreased (>85) in stickleback collected at all streams with previous parathion contamination events. A significant decrease in BChE (78Q) occurred also, however, at one stream where other pesticides but no OPs were found. Because stickleback AChE and BChE differed strongly in their in vitro sensitivity and their response in the field, these enzymes should be considered separately in studies with fish.