Palmisano B W, Clifford P S, Coon R L, Seagard J L, Hoffmann R G, Kampine J P
Department of Anesthesiology, Medical College of Wisconsin, Milwaukee 53226.
Pediatr Res. 1990 Feb;27(2):148-52. doi: 10.1203/00006450-199002000-00013.
The purpose of this study is to describe the developmental course of arterial baroreflex control of heart rate in swine. Tests of baroreflex function were performed with eight conscious piglets serially over their first 2 mo of life. Systemic blood pressure was raised with phenylephrine (pressor test) and lowered with nitroprusside (depressor test), and stimulus-response curves relating heart rate to mean blood pressure were constructed. Baroreflex sensitivity was determined as the slope of the linear portion of the curve. Baroreflex sensitivity decreased with increasing age. Baroreflex sensitivity was not different between pressor and depressor tests except when the piglets were greater than 52 d old and sensitivity was greater with the depressor test. The heart rates at threshold and saturation, and therefore the heart rate response range, shifted to lower heart rates with increasing age. This shift was more than can be accounted for by the simultaneously decreasing resting heart rate.
本研究的目的是描述猪心率的动脉压力反射控制的发育过程。在8只清醒仔猪出生后的前2个月内，对其进行了连续的压力反射功能测试。用去氧肾上腺素升高系统血压（升压试验），用硝普钠降低系统血压（降压试验），并构建心率与平均血压的刺激-反应曲线。压力反射敏感性被确定为曲线线性部分的斜率。压力反射敏感性随年龄增长而降低。除了仔猪大于52日龄且降压试验的敏感性更高外，升压试验和降压试验的压力反射敏感性没有差异。阈值和饱和时的心率，以及因此心率反应范围，随着年龄的增长而转向更低的心率。这种变化超过了同时降低的静息心率所能解释的范围。
