Reproductive endocrine disruption in the freshwater catfish, Heteropneustes fossilis, in response to the pesticide gamma-hexachlorocyclohexane.
Both male and female freshwater catfish, Heteropneustes fossilis, were exposed to safe (SC; 0.1 and 1.0 mg/L) and sublethal (SL; 10 mg/L) concentrations of an agricultural pesticide, gamma-hexachlorocyclohexane (gamma-HCH) for 4 weeks during the active pre-spawning (vitellogenic) phase of their annual reproductive cycle. On the last day of exposure, 18 h before killing, fish were treated intramuscularly (i.m.) with [I-14C]acetic acid (74 kBq per fish). After 4 weeks of exposure, we monitored the effects of gamma-HCH on gonadosomatic index (GSI); on plasma concentrations of gonadotropin (GtH), testostosterone (T), 11-ketotestosterone (11-KT), 17beta-estradiol (E2); and on hepatic incorporation of [I-14C]acetic acid into total phospholipids (TP) and the fractions thereof: phosphatidylcholine (PC), phosphatidylserine (PS), phosphatidylinositol (PI), and phosphatidylethanolamine (PE). In both the sexes, GSI and plasma GtH were decreased significantly in response to gamma-HCH exposure. Plasma T and 11-KT in males, and plasma T and E2 in females declined significantly in response to gamma-HCH exposure. In both the sexes, hepatic incorporation of [I-14C]acetic acid into PS and PI increased significantly, whereas incorporation into TP, PC, and PE was significantly reduced after gamma-HCH exposure. Our findings demonstrated that gamma-HCH exposure depressed GSI, plasma GtH, sex steroids, and [I-14C]acetic acid incorporation into hepatic TP, and had very selective and specific effects on various classes of TP, resulting either from the hypothalamo-hypophyseal-gonadal axis or from direct action on hepatic and steroidogenic enzymes during the pre-spawning phase, causing reproductive endocrine disruptions.
Singh
Pratap B
PB
Department of Zoology, Tilak Dhari College, Jaunpur 222002, India. pratap_p_singh@rediffmail.com
Canario
Adelino V M
AV
D000818:Animals; D002397:Catfishes / Q000502:physiology*; D004703:Endocrine System / Q000187:drug effects*; D004781:Environmental Exposure; D005260:Female; D012739:Gonadal Steroid Hormones / Q000097:blood*; D006066:Gonads / Q000254:growth & development; D001556:Hexachlorocyclohexane / Q000633:toxicity*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000502:physiology; D007306:Insecticides / Q000633:toxicity*; D008297:Male; D010743:Phospholipids / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D012739:Gonadal Steroid Hormones; D007306:Insecticides; D010743:Phospholipids; D014874:Water Pollutants, Chemical; D001556:Hexachlorocyclohexane