title: Evaluation of sublethal effects of dichlorvos upon Caenorhabditis elegans based on a set of end points of toxicity.
abstract: The primary objective of this study was to examine a possible correlation among the three endpoints of toxicity, namely, stress gene expression (hsp16), feeding, and acetylcholinesterase (AChE) activity in transgenic C. elegans (hsp16-lacZ) exposed to sublethal concentrations of dichlorvos, an organophosphorus insecticide. Worms exposed to dichlorvos (at 5, 40, and 80 microM) exhibited a concentration-dependent inhibition in feeding with total cessation in feeding occurring beyond 4 h of exposure. Concomitantly, marked and dose-dependent inhibition (69%-90%) of AChE was also evident after 4 h of exposure. Induction of heat shock protein (Hsp) was evident after 4 h of exposure (as seen from quantitative analysis), although maximum expression of Hsp was evident only after 24 h of exposure (as evident from qualitative analysis). Interestingly, the Hsp induction was restricted only to the pharyngeal region. Significant correlation was discernible between the three evaluated end points suggesting their possible interrelated role in the physiological dysfunctions evoked by sublethal concentrations of dichlorvos.
authors.affiliation: Food Protectants and Infestation Control Department, Central Food Technological Research Institute (CSIR lab), Mysore, India.
authors.forename: Kisan B
authors.initials: KB
authors.lastname: Jadhav
authors.forename: Padmanabhan Sharda
authors.initials: PS
authors.lastname: Rajini
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000201:enzymology; D004006:Dichlorvos / Q000633:toxicity*; D023381:Endpoint Determination; D005247:Feeding Behavior / Q000187:drug effects; D017930:Genes, Reporter; D006360:Heat-Shock Proteins / Q000378:metabolism; D007928:Lethal Dose 50; D016019:Survival Analysis; D013997:Time Factors; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D006360:Heat-Shock Proteins; D004006:Dichlorvos; D000110:Acetylcholinesterase; D001616:beta-Galactosidase