title: Characterization and in vitro sensitivity of cholinesterases of gilthead seabream (Sparus aurata) to organophosphate pesticides.
abstract: The characterization of cholinesterase activity in brain and muscle of gilthead seabream was carried out using four specific substrates and three selective inhibitors. In addition, Kmand Vmaxwere calculated from the Michaelis-Menten equation for ASCh and BSCh substrates. Finally, the in vitro sensitivity of brain and muscle cholinesterases to three organophosphates (OPs) was also investigated by estimating inhibition kinetics. The results indicate that AChE is the enzyme present in the brain, whereas in muscle, a typical AChE form is present along with an atypical form of BChE. Very low ChE activity was found in plasma with all substrates used. The inhibitory potency of the studied OPs on brain and muscle AChEs based on bimolecular inhibition constants (ki) was: omethoate < dichlorvos < azinphosmethyl-oxon. Furthermore, muscle BChE was found to be several orders of magnitude (from 2 to 4) more sensitive than brain and muscle AChE inhibition by dichlorvos and omethoate.
authors.affiliation: Toxicology Laboratory, Faculty of Marine and Environmental Sciences, University of Cádiz, Polígono Río San Pedro s/n, 11510, Puerto Real, Cádiz, Spain. gemma.albendin@uca.es.
authors.forename: G
authors.initials: G
authors.lastname: Albendín
authors.affiliation: Toxicology Laboratory, Faculty of Marine and Environmental Sciences, University of Cádiz, Polígono Río San Pedro s/n, 11510, Puerto Real, Cádiz, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Arellano
authors.affiliation: Analytical Chemical Department, Faculty of Marine and Environmental Sciences, University of Cádiz, Polígono Río San Pedro s/n, 11510, Puerto Real, Cádiz, Spain.
authors.forename: M P
authors.initials: MP
authors.lastname: Mánuel-Vez
authors.affiliation: Institute of Marine Sciences of Andalucía (ICMAN-CSIC), Avda. República Saharaui s/n, 11510, Puerto Real, Cádiz, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Sarasquete
authors.affiliation: Toxicology Laboratory, Faculty of Marine and Environmental Sciences, University of Cádiz, Polígono Río San Pedro s/n, 11510, Puerto Real, Cádiz, Spain.
authors.forename: M I
authors.initials: MI
authors.lastname: Arufe
mesh_terms: D000818:Animals; D001387:Azinphosmethyl / Q000031:analogs & derivatives* / Q000633:toxicity; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D002802:Cholinesterases / Q000097:blood / Q000378:metabolism*; D004006:Dichlorvos / Q000633:toxicity*; D004117:Dimethoate / Q000031:analogs & derivatives* / Q000633:toxicity; D029941:Fish Proteins / Q000037:antagonists & inhibitors / Q000097:blood / Q000378:metabolism*; D007306:Insecticides / Q000633:toxicity*; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D021541:Sea Bream / Q000097:blood / Q000378:metabolism
chemical_list: D015415:Biomarkers; D002800:Cholinesterase Inhibitors; D029941:Fish Proteins; D007306:Insecticides; D001387:Azinphosmethyl; C002302:dimethoxon; D004006:Dichlorvos; C034434:azinphosmethyl oxon; D002802:Cholinesterases; D004117:Dimethoate
keywords: Biomarker; Cholinesterase; Gilthead seabream; Inhibition kinetics; Organophosphate; Sparus aurata