title: Rho-kinase inhibition attenuates acute hypoxic fetoplacental vasoconstriction in the rat.
abstract: The vessels on the fetal side of the placenta differ from most other vascular beds except the lungs in that they respond to acute hypoxia by vasoconstriction. An essential role of calcium influx in the mechanism of this hypoxic fetoplacental vasoconstriction (HFPV) has been shown previously. That finding does not, however, exclude the possible involvement of other mechanisms of vascular tone regulation. In this study we tested the hypothesis that Rho-kinase-mediated calcium sensitization is involved in HFPV. We used a model of isolated rat placenta dually perfused (from both the maternal and fetal side) with Krebs salt solution saturated with normoxic and hypoxic gas mixture respectively at constant flow rate. Rho-kinase pathway was inhibited by fasudil (10 microM). We found that fasudil reduced basal normoxic fetoplacental vascular resistance and completely prevented HFPV. This suggests that the activity of Rho-kinase signaling pathway is essential for HFPV.
authors.affiliation: Department of Physiology, Second Faculty of Medicine, Charles University, Prague, Czech Republic. petrkaf@yahoo.com
authors.forename: P
authors.initials: P
authors.lastname: Kafka
authors.forename: O
authors.initials: O
authors.lastname: Vajnerová
authors.forename: J
authors.initials: J
authors.lastname: Herget
authors.forename: V
authors.initials: V
authors.lastname: Hampl
mesh_terms: D000818:Animals; D002118:Calcium; D005260:Female; D000860:Hypoxia / Q000378:metabolism* / Q000503:physiopathology; D010920:Placenta / Q000098:blood supply; D021041:Placental Circulation / Q000502:physiology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D014655:Vascular Resistance / Q000502:physiology; D014661:Vasoconstriction / Q000502:physiology*; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D054460:rho-Associated Kinases; D002118:Calcium