title: The effect of malathion, an organophosphate, on the plasma FSH, 17 beta-estradiol and progesterone concentrations and acetylcholinesterase activity and conception in dairy cattle.
abstract: The effect of malathion on jugular plasma concentrations of follicle-stimulating hormone (FSH), estradiol (E2), progesterone (P4) and acetylcholinesterase (AchE) on conception in dairy cattle during a cloprostenol (prostaglandin F2 alpha analogue, PG)-induced estrus was studied. Malathion (1 mg/kg, intraruminally) given at the onset of estrus (48 h after PG) did not alter the plasma FSH or E2 concentrations but significantly (P less than 0.05) inhibited plasma P4 concentration. The mean P4 concentration in the malathion-treated group on days 8 and 12 were 0.8 +/- 0.4 and 1.0 +/- 0.5 ng/ml, as compared to 2.6 +/- 0.0 and 2.4 +/- 0.3 ng/ml in the control group. There was a nonsignificant (P greater than 0.05) inhibition of plasma AchE activity in malathion-treated cattle. Conception was 16.6% in malathion-treated cows and 50% in controls. Inhibition of progesterone secretion and poor conception occurred after the single intraruminal dose of malathion at the onset of estrus.
authors.affiliation: Department of Pharmacology, Veterinary College, University of Agricultural Sciences, Bangalore, India.
authors.forename: N
authors.initials: N
authors.lastname: Prakash
authors.forename: K
authors.initials: K
authors.lastname: Narayana
authors.forename: G S
authors.initials: GS
authors.lastname: Murthy
authors.forename: N R
authors.initials: NR
authors.lastname: Moudgal
authors.lastname: Honnegowda
mesh_terms: D000110:Acetylcholinesterase / Q000097:blood*; D000818:Animals; D002417:Cattle / Q000097:blood / Q000502:physiology*; D004958:Estradiol / Q000097:blood; D004971:Estrus / Q000187:drug effects; D005260:Female; D005306:Fertilization / Q000187:drug effects*; D005640:Follicle Stimulating Hormone / Q000097:blood; D006728:Hormones / Q000097:blood*; D008294:Malathion / Q000633:toxicity*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood
chemical_list: D006728:Hormones; D011374:Progesterone; D004958:Estradiol; D005640:Follicle Stimulating Hormone; D000110:Acetylcholinesterase; D008294:Malathion