Characterization and in vitro sensitivity of cholinesterases of gilthead seabream (Sparus aurata) to organophosphate pesticides
- 205 Downloads
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, K m and V max were 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 (k i ) 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.
KeywordsGilthead seabream Sparus aurata Biomarker Organophosphate Cholinesterase Inhibition kinetics
The authors are grateful to the Laboratory of Marine Culture at University of Cádiz for providing the experimental fish used in this study. This work was supported by Plan Nacional de I + D, Sciences and Technology Minister (Project: CTM2004-05718) and in part by Plan Andaluz de Investigación (PAI group: RNM-345).
- Assis CRD, Bezerra RS, Carvalho LB Jr (2011) Fish cholinesterases as biomarkers of organophosphorus and carbamate pesticides. In: Stoytcheva M (ed) Pesticides in the modern world - Pests control and pesticides exposure and toxicity assessment. InTech, pp 253–278. doi: 10.5772/20777
- Chuiko GM (2000) Comparative study of acetylcholinesterase and butyrylcholinesterase in brain and serum of several freshwater fish: specific activities and in vitro inhibition by DDVP, and organophosphorus pesticide. Comp Biochem Physiol 127C:233–242. doi: 10.1016/S0742-8413(00)00150-X Google Scholar
- Kamrin MA (2000) Pesticides profiles. Toxicology, environmental impact, and fate. CRC Press LLC, CRC Press LLCGoogle Scholar
- Quintaneiro C, Monteiro M, Pastorinho R, Soares AMVM, Noqueira AJA, Morgado F, Guilhermino L (2006) Environmental pollution and natural populations: a biomarkers case study from the Iberian Atlantic Coast. Mar Pollut Bull 52:1406–1413. doi: 10.1016/j.marpolbul.2006.04.002 CrossRefPubMedGoogle Scholar
- Sturm A, da Silva de Assis HC, Hansen PD (1999) Cholinesterases of marine teleost fish: enzymological characterization and potential use in the monitoring of neurotoxic contamination. Mar Environ Res 47:389–398. Correction: Mar Environ Res 49(2000):95. doi: 10.1016/S0141-1136(98)00127-5
- Sturm A, Wogran J, Segner H, Liess M (2000) Different sensitivity to organophosphates of acetylcholinesterase and butyrylcholinesterase from three-spined stickeback (Gasterosteus aculeatus): application in biomonitoring. Environ Toxicol Chem 19:1607–1615. doi: 10.1002/etc.5620190618 CrossRefGoogle Scholar