Effect of the khat alkaloid (+)norpseudoephedrine on uteroplacental blood flow in the guinea pig.
In order to investigate effects of khat chewing on uteroplacental blood flow (+)norpseudoephedrine (NPE) infusions were given to 11 anesthetized guinea pigs in late pregnancy (62-66 days) after unilateral uterine artery ligation at days 30-32. Regional blood flows were determined with radioactive microspheres. Mean arterial blood pressure increased with 25% and heart rate with 9% during NPE infusion. Myoendometrial blood flow was reduced by 31%. Placental vascular resistance (PVR) increased by 56% in the control horn (17 fetuses) and by 82% in the ligated horn (17 fetuses). This vasoconstriction was counteracted by the systemic vasopressor response since placental blood flow remained unchanged. When considering only the 13 growth-retarded fetuses, however, PVR increased by 98% and a 19% reduction of placental blood flow could be demonstrated. These results suggest that the placenta of the growth-retarded fetus may be more sensitive to adrenergic stimulation than the normal placenta. Furthermore, since one of the active constituents of khat, (+)norpseudoephedrine, causes vasoconstriction in the uteroplacental vascular bed it is possible that khat chewing could reduce placental blood flow and, as a consequence, impair fetal growth.
D000818:Animals; D001067:Appetite Depressants / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D029754:Catha; D005260:Female; D005333:Fetus / Q000187:drug effects; D006168:Guinea Pigs; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010665:Phenylpropanolamine / Q000494:pharmacology*; D010920:Placenta / Q000098:blood supply* / Q000187:drug effects; D010936:Plant Extracts; D011247:Pregnancy; D012039:Regional Blood Flow / Q000187:drug effects; D014599:Uterus / Q000098:blood supply*; D014655:Vascular Resistance / Q000187:drug effects
D001067:Appetite Depressants; D010936:Plant Extracts; C005331:norpseudoephedrine; D010665:Phenylpropanolamine