Pathogenesis of hyperadrenergic orthostatic hypotension. Evidence of disordered venous innervation exclusively in the lower limbs.
Pathogenesis of hyperadrenergic orthostatic hypotension. Evidence of disordered venous innervation exclusively in the lower limbs.
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高肾上腺素能体位性低血压的发病机制。
DOI：
10.1172/jci114878
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发表时间：
1990
期刊：
影响因子：
--
通讯作者：
Streeten,DH
中科院分区：
文献类型：
--
作者：
Streeten,DH
本文对8例高肾上腺素性直立性低血压的发病机制进行了研究。通过充气压力服（MAST）纠正了异常的直立性变化，证实了先前腿部静脉血液过度重力淤积的证据。静脉L-去甲肾上腺素输注升高舒张压，与正常受试者中输注诱导的血浆去甲肾上腺素浓度增量的关系相同，表明小动脉反应正常。用线性可变差动Transformer（LVDT）测量静脉对输注L-去甲肾上腺素的收缩反应。患者手部静脉的静脉反应在正常手部静脉反应的95%置信限内，7名正常受试者足部静脉的反应也在95%置信限内。然而，患有肾上腺素能直立性低血压的患者的足静脉和患有“弥漫性”自主神经衰竭的患者的手和足静脉对去甲肾上腺素超敏感，如通过log（去甲肾上腺素输注速率）对静脉扩张性的百分比减少的回归的陡峭斜率和显著较低的ED 50（即，去甲肾上腺素输注速率诱导静脉扩张性降低50%）。研究结果表明，这些患者的下肢静脉解剖或功能性节后去神经支配导致过度重力性血液淤积，从而导致直立性低血压。
The pathogenesis of hyperadrenergic orthostatic hypotension was studied in eight patients. Correction of the abnormal orthostatic changes by an inflated pressure suit (MAST) confirmed previous evidence of excessive gravitational pooling of blood in the leg veins. Intravenous L-norepinephrine infusion raised diastolic blood pressure in the same relationship to the infusion-induced increments in plasma norepinephrine concentrations as in normal subjects, indicating normal arteriolar responses. Contractile responses of the veins to infused L-norepinephrine were measured with a linear variable differential transformer (LVDT). The venous responses of hand veins in the patients fell within the 95% confidence limits of the responses of normal hand veins, as did the responses of foot veins in the seven normal subjects. However, foot veins of the patients with hyperadrenergic orthostatic hypotension, and both hand and foot veins of patients with "diffuse" autonomic failure, were supersensitive to norepinephrine, as reflected by a steeper slope of the regression of log (norepinephrine infusion rate) on percentage reduction in venous distensibility, and a significantly lower ED50 (i.e., norepinephrine infusion rate that induced 50% reduction in venous distensibility). The findings suggest anatomical or functional postganglionic denervation of lower limb veins causing excessive gravitational blood pooling with consequent orthostatic hypotension in these patients.Images