Anderson E A, Wallin B G, Mark A L
Hypertension. 1987 Jun;9(6 Pt 2):III114-9. doi: 10.1161/01.hyp.9.6_pt_2.iii114.
Mental stress, which increases blood pressure and heart rate, increases forearm blood flow but does not change calf blood flow. The purpose of this study was to determine if mental stress increases muscle sympathetic nerve activity in the leg and causes a dissociation of muscle sympathetic nerve activity in the arm and the leg. We recorded heart rate, blood pressure, and efferent sympathetic nerve activity during mental stress (4 minutes of mental arithmetic) in 13 healthy men. Microelectrodes were inserted percutaneously into a fascicle of the peroneal nerve (leg) and radial nerve (arm) to measure sympathetic discharge to muscle. In Study 1, leg muscle sympathetic nerve activity was recorded in seven subjects. Mental stress significantly increased heart rate and blood pressure. Despite the increased blood pressure (which would be expected reflexly to inhibit sympathetic nerve activity), leg muscle sympathetic nerve activity (in total integrated activity, bursts per 100 heart beats or bursts per minute) increased significantly during stress. Further, whereas heart rate and blood pressure returned to normal during recovery, leg muscle sympathetic nerve activity remained elevated during recovery. In Study 2, simultaneous recordings were made of arm and leg muscle sympathetic nerve activity in six subjects. Mental stress increased heart rate and arterial pressure. Leg muscle sympathetic nerve activity again increased significantly during stress and remained elevated during recovery. In contrast, arm muscle sympathetic nerve activity did not change during stress. However, arm muscle sympathetic nerve activity increased significantly during recovery after stress. These studies indicate that a sympathoexcitatory influence of mental stress overrides or inhibits baroreceptor control of leg sympathetic nerve activity and stress causes a dissociation of arm and leg muscle sympathetic nerve activity with increased outflow to the leg but not to the arm. These observations may contribute to differences in blood flow to arm and leg during mental stress.
精神压力会升高血压和心率，增加前臂血流量，但不会改变小腿血流量。本研究的目的是确定精神压力是否会增加腿部肌肉交感神经活动，并导致手臂和腿部肌肉交感神经活动的分离。我们记录了13名健康男性在精神压力（4分钟心算）期间的心率、血压和传出交感神经活动。将微电极经皮插入腓神经（腿部）和桡神经（手臂）的一个束中，以测量对肌肉的交感神经放电。在研究1中，记录了7名受试者的腿部肌肉交感神经活动。精神压力显著增加了心率和血压。尽管血压升高（预期会反射性抑制交感神经活动），但在压力期间腿部肌肉交感神经活动（以总积分活动、每100次心跳的爆发次数或每分钟的爆发次数计）显著增加。此外，虽然心率和血压在恢复过程中恢复正常，但腿部肌肉交感神经活动在恢复过程中仍保持升高。在研究2中，对6名受试者同时记录了手臂和腿部肌肉交感神经活动。精神压力增加了心率和动脉压。腿部肌肉交感神经活动在压力期间再次显著增加，并在恢复过程中保持升高。相比之下，手臂肌肉交感神经活动在压力期间没有变化。然而，压力后恢复期间手臂肌肉交感神经活动显著增加。这些研究表明，精神压力的交感兴奋影响超越或抑制了压力感受器对腿部交感神经活动的控制，并且压力导致手臂和腿部肌肉交感神经活动的分离，腿部的交感神经流出增加而手臂没有。这些观察结果可能有助于解释精神压力期间手臂和腿部血流量的差异。
