Greenwood J P, Stoker J B, Walker J J, Mary D A
Department of Cardiology, St James's University Hospital, Leeds, UK.
J Hypertens. 1998 May;16(5):617-24. doi: 10.1097/00004872-199816050-00009.
Microneurographic assessment of processed bursts that represent multi-unit nerve discharge has suggested that sympathetic hyperactivity occurs in pregnancy induced hypertension and pre-eclampsia in comparison with normal pregnancy.
To examine the differences between peripheral sympathetic outputs in pregnancy-induced hypertension and normal pregnancy by directly measuring single impulses of neural discharge.
We compared the sympathetic neural discharge at rest and its reflex responses in subjects with pregnancy-induced hypertension and normal pregnancy and re-examined their progress at least 6 weeks post partum. The patients with pregnancy-induced hypertension were hospital in-patients for whom the diagnosis could be strictly defined and the normally pregnant women were recruited to match the former.
Standard microneurography was performed to quantify single impulses of action potentials, together with the processed multi-unit bursts from fibres innervating the leg muscles. We measured neural discharge with vascular vasoconstrictive properties, heart rate and finger arterial blood pressure at rest and their responses to standard isometric hand-grip exercise and cold pressor tests.
As expected, patients with pregnancy-induced hypertension (n = 13) had higher levels of finger arterial blood pressure than did women with normal pregnancies (n = 11). The number of single impulses of action potentials (per min and per 100 cardiac beats) in resting patients with pregnancy-induced hypertension was more than three times greater than that in resting women with normal pregnancies, and the number of multi-unit bursts was twofold greater. After delivery of their child, sympathetic activity and heart rate in nine patients decreased, but finger arterial blood pressure decreased in patients with pregnancy-induced hypertension only.
From results of cross-sectional and longitudinal studies, pregnancy-induced hypertension is associated with a greater resting sympathetic output than that of women with normal pregnancies. Follow-up data after parturition suggest that this hyperactivity is not the only cause of hypertension.
对代表多单位神经放电的加工脉冲进行微神经图评估表明，与正常妊娠相比，妊娠高血压和先兆子痫患者存在交感神经过度活跃的情况。
通过直接测量神经放电的单个冲动，研究妊娠高血压与正常妊娠外周交感神经输出的差异。
我们比较了妊娠高血压患者和正常妊娠受试者静息时的交感神经放电及其反射反应，并在产后至少6周重新检查了他们的情况。妊娠高血压患者为住院患者，其诊断可严格界定，正常孕妇经招募以匹配前者。
采用标准微神经图技术量化动作电位的单个冲动，以及来自支配腿部肌肉纤维的加工多单位脉冲。我们测量了静息时具有血管收缩特性的神经放电、心率和手指动脉血压，以及它们对标准等长握力运动和冷加压试验的反应。
正如预期的那样，妊娠高血压患者（n = 13）的手指动脉血压水平高于正常妊娠女性（n = 11）。妊娠高血压静息患者动作电位的单个冲动数量（每分钟和每100次心跳）比正常妊娠静息女性多三倍以上，多单位脉冲数量多两倍。分娩后，9例患者的交感神经活动和心率下降，但仅妊娠高血压患者的手指动脉血压下降。
横断面和纵向研究结果表明，妊娠高血压与静息时比正常妊娠女性更大的交感神经输出有关。产后随访数据表明，这种过度活跃不是高血压的唯一原因。
