Hamed RR, Elawa ShE Farid NM, Ataya FS (1999) Evaluation of detoxification enzyme levels in Egyptian catfish, Clarias lazera exposed to dimethoate. Bull. Environ. Contam. Toxicol. 63, 789-796. ISSN: 0007-4861 (Impact factor 1.0), DOI: 10.1007/s0012899
Living organisms, including fish, possess a pre-existing defence mechanism
capable to eliminate toxic chemicals either by enzymatic degradation, conjugation
or excretion. Fish are sensitive indicators of residues in water in which the
amounts of pesticides are too small to be reliably analysed chemically. Laboratory
model ecosystems of microsomes are now well-established tools for investigating
the environmental toxicology of pesticides. The xenobiotic metabolizing enzymes
have been used as biomarkers for chemical induced cytotoxicity including
carcinogenesis in mammals and aquatic communities (Hendrich and Pilot 1987;
Bailey et al. 1992; Naqvi and Vaishnavi 1993; Kirby et al. 1995). Among these
enzymes are glutathione peroxidase (E.C. 1.11.1.19, GSH PX). It catalyses the
reduction of hydroperoxidase by reduced glutathione. Glutathione reductase
(E.C. 1.6.4.2), catalyses the reduction of oxidized glutathione using NADPH as a
hydrogen doner. Glutathione-S-transferases (E.C.2.5.1.18) are a group of enzymes
that catalyse the chemical conjugation of reduced glutathione, to a variety of
electrophilic compounds (Lauren et al. 1989).
Glutathione S. transferases (GSTs; EC. 2.5.1.18) are a large family of multifunctional enzymes that play crucial roles in the metabolism and inactivation of a broad range of xenobiotic compounds.…
Background: In the wake of the warning by WHO that the prevalence of dementia may have a rise of 125% in the Middle East by 2050, identification of the genetic risk factors in Arab populations is…