Sugiyama Y, Matsukawa T, Shamsuzzaman A S, Okada H, Watanabe T, Mano T
Department of Autonomic and Behavioral Neurosciences, Research Institute of Environmental Medicine, Nagoya University, Japan.
J Appl Physiol (1985). 1996 Mar;80(3):869-75. doi: 10.1152/jappl.1996.80.3.869.
We studied the effects of aging on alpha-receptor-mediated vasoconstrictive responses to sympathetic nerve activity in 16 healthy aged [75.8 +/- 2.7 (SE) yr] and young men (33.8 +/- 2.0 yr). Muscle sympathetic nerve activity (MSNA), heart rate, and blood pressure were analyzed during slow respiration (0.1 Hz). Peak amplitude and phase were calculated from a cosine function fitted with 0.1 Hz by using the least squares method. The latency of the pressor response to MSNA, defined as lag time from the peak of MSNA to diastolic blood pressure, was significantly longer in the aged than the young group (7.1 +/- 0.3 vs. 5.4 +/- 0.4 s; P < 0.01). The extent of pressor response to MSNA, defined as diastolic blood pressure rise in response to increase in total MSNA, was significantly lower in the aged than the young group (0.038 +/- 0.006 vs. 0.099 +/- 0.024 mmHg/unit, P < 0.001). These results suggest that alpha-receptor-mediated vasoconstrictive responses to MSNA may be attenuated in the elderly.
我们研究了衰老对16名健康老年人[75.8±2.7（标准误）岁]和年轻男性（33.8±2.0岁）中α受体介导的对交感神经活动的血管收缩反应的影响。在慢呼吸（0.1Hz）期间分析肌肉交感神经活动（MSNA）、心率和血压。通过使用最小二乘法从拟合0.1Hz的余弦函数计算峰值幅度和相位。对MSNA的升压反应潜伏期定义为从MSNA峰值到舒张压的滞后时间，老年人明显长于年轻组（7.1±0.3对5.4±0.4秒；P<0.01）。对MSNA的升压反应程度定义为对总MSNA增加的反应中舒张压的升高，老年人明显低于年轻组（0.038±0.006对0.099±0.024mmHg/单位，P<0.001）。这些结果表明，老年人中α受体介导的对MSNA的血管收缩反应可能减弱。
