Edelstone D I, Merick R E, Caritis S N, Mueller-Heubach E
Am J Obstet Gynecol. 1980 Nov 15;138(6):703-7. doi: 10.1016/0002-9378(80)90092-7.
In nine chronically catheterized fetal lambs (120 to 135 days; term 147 days) umbilical venous blood flow and its distribution were measured by the radionuclide-labeled microsphere technique before and during autonomic blockade with atropine (0.20 to 0.25 mg/kg; seven studies) or phentolamine (0.10 to 0.12 mg/kg; six studies). Atropine significnatly increased mean fetal heart rate (182 to 207 beats/min), descending aortic blood pressure (49 to 55 mm Hg), and umbilical venous blood flow (210 to 239 ml/min/kg fetus), without changing umbilical venous blood pressure. Phentolamine decreased mean descending aortic pressure (48 to 45 mm Hg), but did not affect heart rate, umbilical venous blood pressure, or umbilical venous blood flow. Neither atropine nor phentolamine altered the distribution of umbilical venous blood flow to the ductus venosus, the liver, or the other fetal organs. These data indicate that the cholinergic nervous system only indirectly affects the basal umbilical venous blood flow in the near-term fetal lamb. This effect is small and is secondary to associated changes in heart rate and arterial blood pressure. Neither the cholinergic nor the alpha-adrenergic systems influence the basal distribution of umbilical venous blood flow.
在9只长期插有导管的胎羊（120至135日龄；足月为147日龄）中，在用阿托品（0.20至0.25毫克/千克；7项研究）或酚妥拉明（0.10至0.12毫克/千克；6项研究）进行自主神经阻滞之前和期间，通过放射性核素标记微球技术测量脐静脉血流及其分布。阿托品显著增加平均胎儿心率（从182次/分钟增至207次/分钟）、降主动脉血压（从49毫米汞柱增至55毫米汞柱）和脐静脉血流（从210毫升/分钟/千克胎儿增至239毫升/分钟/千克胎儿），而脐静脉血压不变。酚妥拉明降低平均降主动脉压（从48毫米汞柱降至45毫米汞柱），但不影响心率、脐静脉血压或脐静脉血流。阿托品和酚妥拉明均未改变脐静脉血流在静脉导管、肝脏或其他胎儿器官中的分布。这些数据表明，胆碱能神经系统仅间接影响近足月胎羊的基础脐静脉血流。这种影响很小，是心率和动脉血压相关变化的继发结果。胆碱能系统和α-肾上腺素能系统均不影响脐静脉血流的基础分布。
