Effect of hexoprenaline on uteroplacental blood flow in the pregnant rat.
The effect of beta-adrenergic agonists on uteroplacental blood flow is controversial. Human studies, with the use of indirect methods to assess uteroplacental blood flow, show conflicting results. Animal studies in the near-term pregnant sheep model have the disadvantages that the sheep has a syndesmochorial placenta and that the uteroplacental vessels are thought to be maximally dilated near term. The effect of hexoprenaline, a new beta 2-sympathomimetic drug, was assessed in the awake pregnant rat on day 14 of gestation by means of the radionuclide-labeled microsphere method. Hexoprenaline increased placental blood flow by 198% and distribution of cardiac output to the placentas by 229%. Renal blood flow was reduced by 24%. Saline solution administration produced no significant effects.
D000818:Animals; D002302:Cardiac Output; D005260:Female; D005682:Gadolinium; D006594:Hexoprenaline / Q000494:pharmacology*; D008431:Maternal-Fetal Exchange / Q000187:drug effects*; D008863:Microspheres; D010627:Phenethylamines / Q000494:pharmacology*; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D011868:Radioisotopes; D051381:Rats; D011919:Rats, Inbred Strains; D012039:Regional Blood Flow / Q000187:drug effects; D012079:Renal Circulation / Q000187:drug effects; D013268:Stimulation, Chemical; D014001:Tin; D014599:Uterus / Q000098:blood supply*
D010627:Phenethylamines; D011868:Radioisotopes; D014001:Tin; D005682:Gadolinium; D006594:Hexoprenaline