STATEMENTS OF THE PROBLEM: The use of @entity12078 -Adrenergic Receptor (AR) agonists and the potential use of alpha1-AR blockers as tocolytics raise the question of how they influence placental circulation. The receptor profile was characterized via the amounts of the mRNA of alpha1-AR subtypes and @entity12078 -ARs. The mRNAs were detected by reverse transcription-polymerase chain reaction. Electric field stimulation (EFS) was applied to test the pharmacological reactivity of the placental vessels. Expressions of @entity12078 - and all subtypes of alpha1-AR mRNA were demonstrated in @entity1 placental vessels, and were significantly higher in the arteries. A significant difference was not found between the veins and the arteries as concerns the amount of alpha1D-AR mRNA. There was a preponderance of @entity10598 - and @entity11113 mRNA as compared to alpha1D-AR mRNA both in the arteries and in the veins. @entity2162 agonists and alpha1-AR antagonists antagonized the EFS-induced contractions of the placental arteries in a dose-dependent manner. These effects were significantly less marked on veins at all applied doses. Urapidil antagonized the EFS-induced contractions of both the placental arterial and vein rings in a dose-dependent manner. The @entity12078 -, @entity10598 -, and @entity11113 are the important subtypes involved in the regulation of the contractility of the @entity1 term placental vessels. The possible increase in placental blood flow mediated by these ARs can even be beneficial during pregnancy. Accordingly, the use of @entity2162 agonists and the potential use of alpha1-blockers as tocolytics seem safe on the basis of in vitro examinations as concerns the placental circulation.

Role of adrenergic receptor subtypes in the control of XXXX placental blood vessels.

@entity1 :: ('9606', 'Species') :: ['human'] @entity2162 :: ('154', 'Gene') :: ['beta2-AR'] @entity10598 :: ('773', 'Gene') :: ['alpha1A'] @entity12078 :: ('10383', 'Gene') :: ['beta2'] @entity11113 :: ('147', 'Gene') :: ['alpha1B-AR']
@entity1 :: (9606,Species) :: ['human']
