Cocaine augments contractility of the pregnant human uterus by both adrenergic and nonadrenergic mechanisms.

Published

Journal Article

OBJECTIVE: Our purpose was to evaluate the mechanisms of cocaine's effect on both spontaneous and agonist-induced contractility of pregnant human myometrium. STUDY DESIGN: Myometrium was obtained from 42 women at term who were undergoing cesarean section. Myometrial strips were suspended in contraction baths and isometric contractions were measured. Tissue was exposed to various combinations of cocaine, prazosin, desipramine, benzoylecgonine, and procaine. Spontaneous contractility and the contractile responses to increasing concentrations of methoxamine and oxytocin were measured and compared. RESULTS: Cocaine increased spontaneous myometrial contractility by more than threefold. Prazosin, an alpha-adrenergic antagonist, blocked this effect only for the first 35 minutes of exposure. The cumulative concentration-response to the alpha-adrenergic agonist methoxamine was increased by cocaine in terms of both sensitivity and maximal response. The maximal response to oxytocin, but not the sensitivity, was increased by cocaine by an effect that could not be blocked by prazosin. CONCLUSION: Cocaine augments spontaneous and agonist-induced contractility of pregnant human myometrium by mechanisms that appear to be both alpha-adrenergic and nonadrenergic in nature.

Full Text

Duke Authors

Cited Authors

  • Hurd, WW; Betz, AL; Dombrowski, MP; Fomin, VP

Published Date

  • May 1998

Published In

Volume / Issue

  • 178 / 5

Start / End Page

  • 1077 - 1081

PubMed ID

  • 9609587

Pubmed Central ID

  • 9609587

International Standard Serial Number (ISSN)

  • 0002-9378

Digital Object Identifier (DOI)

  • 10.1016/s0002-9378(98)70551-4

Language

  • eng

Conference Location

  • United States