Ž . Comparative Biochemistry and Physiology Part C 129 2001 265273 Disruption of pituitary-ovarian axis by carbofuran in ž / catfish, Heteropneustes fossilis Bloch Sudipta Chatterjee a , Asok Kumar Dasmahapatra a,b,  , Rama Ghosh a a Department of Animal physiology, Bose Institute, P-1  12 CIT Scheme VII-M, Calcutta 700 054, India b NIEHS Marine and Freshwater Biomedical Sciences Center, Uni  ersity of Wisconsin-Milwaukee, 600 East Greenfield A enue, Milwaukee, WI 53204, USA Received 10 December 2000; received in revised form 23 April 2001; accepted 25 April 2001 Abstract Ž . We investigated whether carbofuran CF , a carbamate pesticide, at sub-lethal concentration had any adverse effects on reproductive function of the Indian catfish , Heteropneustes fossilis. 17-Estradiol content of serum and ovary of Ž. Ž. Ž pre-spawning P and spawning S fish was reduced after sub-lethal concentration of carbofuran treatment 0.5 2 . mgml, 30 days . After 30 days of CF treatment, the serum and ovarian vitellogenin levels of fish at the P stage were also reduced but remained unaltered in the S stage. The staining intensity of the pituitary gonadotrophs of the pre-spawning fish was significantly higher in CF-treated fish compared to controls suggesting the inability of the pituitary gonadotrophs to release gonadotropin following CF treatment. CF thus acts as an antiestrogenic, endocrine-disrupting agent in fish, possibly targeting the pituitary-gonad axis.  2001 Elsevier Science Inc. All rights reserved. Keywords: Catfish; Carbofuran; Pituitary; Estrogen; Vitellogenin 1. Introduction Various synthetic chemicals particularly those widely used in agriculture produce various types of reproductive and developmental disorders in Ž wildlife Copper and Kavlock, 1997; Beard and . Rawlings, 1998 . It is believed that an irreversible effect is induced when animals are exposed to endocrine disrupting chemicals during critically  Corresponding author. Tel.: 1-414-3821746; fax: 1- 414-3821705. Ž . E-mail address: asok@uwm.edu A.K. Dasmahapatra . susceptible phases of sexual differentiation. Be- cause of their habitat, fish are the greatest victims of the endocrine-disrupting chemicals. There are several target organ sites in the fish where an environmental agent could disrupt their en- docrine function. Currently, the most concerning environmental pollutants are those compounds that are suspected to interfere with the normal functions of estrogens. Disruptions of fish reproductive process with alteration in gonad structure by pesticide has Ž been reported Van der Kraak et al., 1992; Sumpter, 1995; Sumpter and Jobling, 1995; Jobling . et al., 1996 . The synthesis of vitellogenin in Clar- 1532-045601$ - see front matter  2001 Elsevier Science Inc. All rights reserved. Ž . PII: S 1 5 3 2 - 0 4 5 6 01 00203-4