title: Malathion exposure induces the endocrine disruption and growth retardation in the catfish, Clarias batrachus (Linn.).
abstract: Many hormones are known for their role in the regulation of metabolic activities and somatic growth in fishes. The present study deals with the effects of malathion (an organophosphorous pesticide) on the levels of metabolic hormones that are responsible for promotion of somatic and ovarian growth of the freshwater catfish, Clarias batrachus. Malathion treatment for thirty days drastically reduced the food intake and body weight of fish. These fish also exhibited a great avoidance to food. Exposure of catfish to malathion reduced the levels of thyroxine (T(4)), triiodothyronine (T(3)), growth hormone (GH), insulin like growth factor-I (IGF-I), testosterone (T) and estradiol-17β (E(2)) in a dose dependent manner during all the studied reproductive phases, in general, except that malathion increased the level of GH during the quiescence phase. Significant reduction in muscle and hepatic protein content also occurred in the malathion-treated fish. Malathion exposure induced lipolysis too in the liver and muscle. The results thus support that malathion treatment disrupts the endocrine functions and the olfactory sensation responsible for food intake and gustatory feeding behavior, which ultimately leads to retardation of fish growth.
authors.affiliation: Department of Zoology, Banaras Hindu University, Varanasi 221 005, Uttar Pradesh, India. lalbhu@yahoo.co.in
authors.forename: Bechan
authors.initials: B
authors.lastname: Lal
authors.forename: Mukesh Kumar
authors.initials: MK
authors.lastname: Sarang
authors.forename: Pankaj
authors.initials: P
authors.lastname: Kumar
mesh_terms: D000818:Animals; D002397:Catfishes; D004435:Eating / Q000187:drug effects; D052244:Endocrine Disruptors / Q000633:toxicity*; D004958:Estradiol / Q000378:metabolism; D013006:Growth Hormone / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008066:Lipolysis / Q000187:drug effects; D008294:Malathion / Q000633:toxicity*; D013739:Testosterone / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism
chemical_list: D052244:Endocrine Disruptors; D014284:Triiodothyronine; D013739:Testosterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D008294:Malathion