Brown D R, Morgan D A, Peuler J D, Thoren P
Department of Internal Medicine, Veterans Administration Hospital, Iowa City, Iowa 52242.
Am J Physiol. 1989 Nov;257(5 Pt 2):R1225-31. doi: 10.1152/ajpregu.1989.257.5.R1225.
The goal of this study was to determine if the baroreflex abnormality previously shown in Dahl-sensitive (DS) rats would increase blood pressure and heart rate (HR) variability. Mean arterial pressure (MAP) and HR were sampled every 2 s for 24 h from Dahl-resistant (DR) and DS rats on low- and high-salt diets (n = 12-13 in each group). MAP +/- SD was significantly elevated in the DS rats on high-salt diets (DSH); the SD of MAP in the DSH rats was also significantly higher compared with similar measurements in rats on high-salt diets (DRH) and DS rats on low-salt diets (DSL) when SD was divided by MAP. MAP was higher at night than during the day in the DSH rats. In contrast, HR and HR variability were not significantly different between the groups. The baroreflex control of HR, determined by means of graded injections of phenylephrine, was least in the DSH rats and increased, respectively, with DSL rats, DRH rats, and DR rats on low-salt diets. There was no significant correlation between the baroreflex control of HR and MAP or the SD of MAP in the DSH rats, suggesting that there is not a simple relationship between baroreflex gain and the overall behavior of MAP in DSH rats.
本研究的目的是确定先前在 Dahl 敏感（DS）大鼠中显示的压力反射异常是否会增加血压和心率（HR）变异性。从食用低、高盐饮食的 Dahl 抵抗（DR）和 DS 大鼠中，每 2 秒采集一次平均动脉压（MAP）和 HR，持续 24 小时（每组 n = 12 - 13）。高盐饮食的 DS 大鼠（DSH）的 MAP +/- SD 显著升高；当 SD 除以 MAP 时，DSH 大鼠的 MAP 的 SD 与高盐饮食大鼠（DRH）和低盐饮食的 DS 大鼠（DSL）的类似测量值相比也显著更高。DSH 大鼠夜间的 MAP 高于白天。相比之下，各组之间的 HR 和 HR 变异性没有显著差异。通过分次注射去氧肾上腺素测定的 HR 的压力反射控制在 DSH 大鼠中最小，分别在 DSL 大鼠、DRH 大鼠和低盐饮食的 DR 大鼠中增加。DSH 大鼠中 HR 的压力反射控制与 MAP 或 MAP 的 SD 之间没有显著相关性，这表明 DSH 大鼠的压力反射增益与 MAP 的整体行为之间不存在简单关系。
