EFFECTS OF FELODIPINE ON UTEROPLACENTAL BLOOD-FLOW IN NORMOTENSIVE RABBITS

The utero-placental blood flow was investigated in anaesthetized normotensive pregnant rabbits after repeated administration of a high dose of the antihypertensive calcium antagonist felodipine and in untreated controls. By means of the microsphere technique blood flow was also determined in the lungs, skin, intestine, skeletal muscle and kidneys during chloralose anaesthesia. Felodipine reduced mean arterial blood pressure, which was associated with a marked reduction in vascular resistance in the skeletal muscle vascular bed, where blood flow was increased seven-fold. In contrast, blood flow to placentae and kidneys were reduced. The pronounced reduction in placental blood flow may limit foetal nutrition and hence explain reported foetal digital defects after administration of high doses of felodipine to pregnant normotensive rabbits.