Kords H
Z Geburtshilfe Perinatol. 1975 Feb;179(1):30-6.
Cardiovascular action, placental passage and metabolism of fenoterol was studied in pregnant guinea pigs following either a single intravenous injection of 4.5 mug/kg or an infusion of 0.45 mug/kg per min. for 1 hour. After a single injection maternal heart rate increased from 212 to 248 beats/min. within the first minute retruning to basal levels after 35 min. Blood pressure decreased from 70 to 63 mm Hg within 6 min. Fetal heart rate remained unchanged during the first 15 min. but decreased lateron. Fenoterol was rapidly eliminated (t 1/2 = 36 min.) and metabolished. Metabolism consisted of a fast (t 1/2 =2,5 min.) and a slow (t 1/2 = 58 min.) component. Little radioactivity was found in fetal plasma following a single injection. Infusion of 0.45 mug/kg min. for 1 hour increased maternal heart rate from 208 to 234 beats/min. and decreased maternal blood pressure from 76 to 66 mg Hg within the first 10 min. Fetal heart rate remained unchanged for the first 15 min., but decreased from 249 to 219 beats/min. the second 15 min. Little radioactivity was found in fetal plasma also following infusion. Only 2 to 6 percent of the radioactivity (0.0lng/ml) were identified as unchanged fenoterol. The low lipophilic property of fenoterol may be responsible for the low permeability of the placental barrier.
在怀孕的豚鼠身上，研究了非诺特罗单次静脉注射4.5微克/千克或每分钟输注0.45微克/千克持续1小时后的心血管作用、胎盘转运及代谢情况。单次注射后，母体心率在第1分钟内从212次/分钟增至248次/分钟，35分钟后恢复至基础水平。血压在6分钟内从70毫米汞柱降至63毫米汞柱。胎儿心率在最初15分钟内保持不变，但随后下降。非诺特罗迅速被清除（半衰期=36分钟）并发生代谢。代谢包括一个快速成分（半衰期=2.5分钟）和一个缓慢成分（半衰期=58分钟）。单次注射后，胎儿血浆中未发现多少放射性。以每分钟0.45微克/千克的速度输注1小时，在最初10分钟内使母体心率从208次/分钟增至234次/分钟，母体血压从76毫米汞柱降至66毫米汞柱。胎儿心率在最初15分钟内保持不变，但在第二个15分钟内从249次/分钟降至219次/分钟。输注后胎儿血浆中也未发现多少放射性。仅2%至6%的放射性（0.01纳克/毫升）被鉴定为未改变的非诺特罗。非诺特罗的低亲脂性可能是胎盘屏障通透性低的原因。
