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Author Mlynarczuk, Jaroslaw ♦ Wrobel, Michal H. ♦ Kotwica, Jan
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword APPLIED LIFE SCIENCES ♦ CONTRACTION ♦ COWS ♦ DDT ♦ MESSENGER-RNA ♦ OXYTOCIN ♦ POLLUTANTS ♦ POLYCHLORINATED BIPHENYLS ♦ PREGNANCY ♦ PROGESTERONE ♦ SECRETION ♦ SYNTHESIS ♦ UTERUS ♦ ANIMALS ♦ AROMATICS ♦ BODY ♦ CATTLE ♦ CHLORINATED AROMATIC HYDROCARBONS ♦ DOMESTIC ANIMALS ♦ FEMALE GENITALS ♦ HALOGENATED AROMATIC HYDROCARBONS ♦ HORMONES ♦ INSECTICIDES ♦ KETONES ♦ MAMMALS ♦ NUCLEIC ACIDS ♦ ORGANIC CHLORINE COMPOUNDS ♦ ORGANIC COMPOUNDS ♦ ORGANIC HALOGEN COMPOUNDS ♦ ORGANS ♦ PEPTIDE HORMONES ♦ PESTICIDES ♦ PITUITARY HORMONES ♦ PREGNANES ♦ PROTEINS ♦ RNA ♦ RUMINANTS ♦ STEROID HORMONES ♦ STEROIDS ♦ VERTEBRATES
Abstract Chloro-organic compounds are persistent environmental pollutants and affect many reproductive processes. Oxytocin (OT) synthesized in luteal cells is a local regulator of ovarian activity and uterine contractions. Therefore the effect of xenobiotics on the OT prohormone synthesis, secretion of OT and progesterone (P4) from luteal cells and on myometrial contractions during early pregnancy in cows was investigated. Luteal cells and myometrial strips from a cow at early pregnancy were treated with polychlorinated biphenyl 77 (PCB 77), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE) and hexachlorocyclohexane (HCH) (1 or 10 ng/ml). The mRNA expression of neurophysin-I/oxytocin (NP-I/OT) and peptidyl-glycine-{alpha}-amidating mono-oxygenase (PGA) and concentration of OT and P4 were determined by RT-PCR and EIA, respectively. Moreover, the effect of xenobiotics given with P4 (12 ng/ml) on the basal and OT (10{sup -7} M) stimulated contractions of myometrial strips was studied. Xenobiotics increased (P < 0.05) OT secretion but DDE only stimulated P4 secretion. The ratio of P4 to OT in culture medium was decreased by all xenobiotics during 9-12 weeks of pregnancy. All xenobiotics, except HCH, increased (P < 0.05) mRNA expression of NP-I/OT during all stages of pregnancy and all treatments decreased (P < 0.05) expression of mRNA for PGA during 9-12 weeks of pregnancy. Myometrial strips were relaxed (P < 0.01) after pre-incubation with P4, while each of the xenobiotics jointly with P4 increased (P < 0.01) myometrial contractions. In conclusion, the xenobiotics used increased both expression of mRNA for genes involved in OT synthesis and secretion of OT from luteal cells. This decreases the ratio of P4 to OT and presumably, in this manner, the chloro-organic compounds can influence uterine contractions and enhance risk of abortions in pregnant females.
ISSN 0041008X
Educational Use Research
Learning Resource Type Article
Publisher Date 2010-09-15
Publisher Place United States
Journal Toxicology and Applied Pharmacology
Volume Number 247
Issue Number 3


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