title: Maneb and paraquat-induced modulation of toxicant responsive genes in the rat liver: comparison with polymorphonuclear leukocytes.
abstract: Experimental studies have shown that toxicant responsive genes, cytochrome P450s (CYPs) and glutathione S-transferases (GSTs) play a critical role in pesticide-induced toxicity. CYPs play pro-oxidant role and GSTs offer protection in maneb (MB) and paraquat (PQ)-induced brain and lung toxicities. The present study aimed to investigate the effect of repeated exposures of MB and/or PQ on lipid peroxidation (LPO), glutathione content (GSH) and toxicant responsive genes, i.e., CYP1A1, 1A2, 2E1, GSTA4-4, GSTA1-1 and GSTA3-3 in the liver and to correlate the same with polymorphonuclear leukocytes (PMNs). A significant augmentation in LPO and reduction in GSH content was observed in a time of exposure dependent manner in the liver and PMNs of MB and/or PQ treated animals. The expression and catalytic activity of CYP2E1 and GSTA4-4 were significantly increased following MB and/or PQ exposure both in the liver and PMNs. Although the expression of GSTA3-3 was increased, the expression of GSTA1-1 was unaltered after MB and/or PQ treatment in both the liver and PMNs. MB augmented the expression and catalytic activity of CYP1A1 in the liver, however, CYP1A2 was unaffected. PQ, on the other hand, significantly increased hepatic CYP1A2 expression and catalytic activity. MB and/or PQ did not produce any significant changes in CYP1A1 and CYP1A2 in PMNs. The results of the study thus demonstrate that MB and PQ differentially regulate hepatic CYP1A1 and CYP1A2 while LPO, GSH, CYP2E1, GSTA4-4 and GSTA3-3 are modulated in the similar fashions both in the liver and PMNs.
authors.affiliation: Indian Institute of Toxicology Research, Lucknow 226 001, India.
authors.forename: Israr
authors.initials: I
authors.lastname: Ahmad
authors.forename: Smriti
authors.initials: S
authors.lastname: Shukla
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Kumar
authors.forename: Brajesh Kumar
authors.initials: BK
authors.lastname: Singh
authors.forename: Devendra Kumar
authors.initials: DK
authors.lastname: Patel
authors.forename: Haushila Prasad
authors.initials: HP
authors.lastname: Pandey
authors.forename: Chetna
authors.initials: C
authors.lastname: Singh
mesh_terms: D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008344:Maneb / Q000633:toxicity*; D009504:Neutrophils / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects; D010269:Paraquat / Q000633:toxicity*; D010575:Pesticides / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D010575:Pesticides; D008344:Maneb; D003577:Cytochrome P-450 Enzyme System; D005982:Glutathione Transferase; D010269:Paraquat