Baroreflex control of the circulation in chronically instrumented fetal lambs.
Baroreflex control of the circulation in chronically instrumented fetal lambs.
复制标题
压力感受反射对长期使用仪器的胎儿羔羊的循环的控制。
DOI：
10.1161/01.res.52.5.589
复制
发表时间：
1983
影响因子：
20.1
通讯作者：
Rudolph,AM
中科院分区：
文献类型：
--
作者：
Itskovitz,J;LaGamma,EF;Rudolph,AM
在18只妊娠120-136天的胎羊上，研究了动脉压力感受器在调节胎儿循环中的作用。结果进行了比较，在三个窦腹主动脉失神经成年羊。9只胎儿接受窦主动脉去神经，9只胎儿作为假手术对照。术后2 - 3天，连续记录心率和血压，并在1小时内进行分析。在失神经支配的胎儿中，观察到动脉压和心率的显著波动。平均动脉压和心率的频率分布曲线在去神经胎儿中显示出更宽和更平坦的曲线。两组平均动脉压和心率无显著差异。然而，作为平均动脉压变异性指数的标准差从对照组的2.7 +/- 0.9（平均值+/-标准差）增加到去神经胎儿的6.5 +/- 2.4，心率的标准差从10.6 +/- 2.1增加到21.5 +/- 5.7。在成年绵羊中，平均动脉压和心率在去神经后第1天增加，并在第3天恢复到接近对照值。平均动脉压的变异性增加，但心率的变异性没有改变。用放射性核素标记微球技术测定胎心输出量及其分布。两组间的合并心室输出量无统计学差异，但去神经胎儿的胎儿体血流量高出27%。计算出的胎体血管阻力在失神经支配的羔羊低31%。提示动脉压力感受器在调节胎儿期动脉血压和心率变异性方面具有重要作用，并可能在维持正常外周血管阻力方面具有重要作用。
The role of the arterial baroreceptors in regulating the fetal circulation was studied in 18 chronically instrumented fetal lambs, 120-136 days gestation. The results were compared to those obtained in three sinoaortic denervated adult sheep. Nine fetuses underwent sinoaortic denervation and nine fetuses served as sham-operated controls. Two to 3 days after surgery, heart rate and blood pressure were recorded continuously and analyzed over 1-hour periods. In the denervated fetuses, marked fluctuations of the arterial pressure and heart rate were observed. Frequency distribution curves for mean arterial pressure and heart rate showed broader and flatter curves in the denervated fetuses. The average mean arterial pressure and heart rate were not significantly different between the two groups. However, the standard deviation as an index of variability of the mean arterial pressure increased from 2.7 +/- 0.9 (mean +/- standard deviation) in the control group to 6.5 +/- 2.4 in the denervated fetuses, and the standard deviation of the heart rate increased from 10.6 +/- 2.1 to 21.5 +/- 5.7. In the adult sheep, mean arterial pressure and heart rate increased on the 1st day after denervation and returned to near control values on the 3rd day. The variability of the mean arterial pressure increased, but that of the heart rate did not change. Fetal cardiac output and its distribution were measured by the radionuclide-labeled microsphere technique. Combined ventricular output was not statistically different between the groups, but the blood flow to the fetal body was 27% higher in the denervated fetuses. The calculated fetal body vascular resistance was 31% lower in the denervated lambs. This study indicates that the arterial baroreceptors are important in regulating variability of the arterial pressure and heart rate in fetal life, and also may have a significant role in maintaining the normal peripheral vascular resistance.