Effect of environmental pollutants on oxytocin synthesis and secretion from corpus luteum and on contractions of uterus from pregnant cows

Journal Article · Wed Sep 15 04:00:00 EDT 2010 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/j.taap.2010.07.003· OSTI ID:21460212

Mlynarczuk, Jaroslaw; Wrobel, Michal H; Kotwica, Jan

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.

• OSTI ID: 21460212
• Journal Information: Toxicology and Applied Pharmacology, Journal Name: Toxicology and Applied Pharmacology Journal Issue: 3 Vol. 247; ISSN TXAPA9; ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ANIMALS
AROMATICS
BODY
CATTLE
CHLORINATED AROMATIC HYDROCARBONS
CONTRACTION
COWS
DDT
DOMESTIC ANIMALS
FEMALE GENITALS
HALOGENATED AROMATIC HYDROCARBONS
HORMONES
INSECTICIDES
KETONES
MAMMALS
MESSENGER-RNA
NUCLEIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANS
OXYTOCIN
PEPTIDE HORMONES
PESTICIDES
PITUITARY HORMONES
POLLUTANTS
POLYCHLORINATED BIPHENYLS
PREGNANCY
PREGNANES
PROGESTERONE
PROTEINS
RNA
RUMINANTS
SECRETION
STEROID HORMONES
STEROIDS
SYNTHESIS
UTERUS
VERTEBRATES