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PERIPHERAL MICROVASCULAR CONTROL MECHANISMS

外周微血管控制机制

基本信息

批准号：
2457962
负责人：
LOUIS A KOMAN
金额：
$ 15万
依托单位：
WAKE FOREST UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-08-15 至 1999-01-31
项目状态：
已结题

项目摘要

Altered activities of daily living and decreased work productivity secondary to pain on exposure to old, "cold intolerance," are a significant societal burden. A better understanding of the mechanisms of microvascular regulation will provide insight into cold intolerance and aid clinical management. The altered digital microvascular blood flow and cold intolerance seen after trauma or with vascular compromise occlusive, vasospastic, or vaso-occlusive disease) affects millions of people. The cold intolerance of Raynaud's disease and scleroderma preferentially affects woman of childbearing age; black women are affected more often than white women. Surgical peripheral sympathectomy, which appears to improve blood flow by interrupting sympathetic vasoconstrictor innervation, is used when less invasive treatment fails. Paradoxically, digital amputation results in complete sympathectomy and cold intolerance of the replanted digit. The mechanism(s) causing post-replantation vascular thermoregulatory abnormalities is not known, but supersensitivity of digital adrenergic receptors may be a partial explanation. This study hypothesizes that the digital microvascular responses to cold stress following complete sympathectomy differ functionally from those following peripheral sympathectomy. Specifically, the initial vasodilation following complete sympathectomy is replaced by vasoconstriction which results from an increased sensitivity of adrenergic receptors to agonist neurotransmitters. In contrast, this marked supersensitivity of adrenergic receptors does not follow peripheral sympathectomy. To test this hypothesis, a rabbit ear model has been developed in which chronic arterial pressure, auricular blood flow conductance, microvascular perfusion, and microvascular diameters can be monitored in awake, unanesthetized animals pre- and post-sympathectomy and while receptor agonist/antagonists are being manipulated. An acute rabbit ear preparation has also been developed to characterize adrenergic receptor subtypes participating in peripheral microvascular control by direct observation of the microcirculation during application of alpha-1 and alpha-2 agonists and antagonists. Five separate protocols will establish: l) the adrenergic receptor subtypes responsible for control of auricular blood flow, 2) the effect of sympathectomy on auricular conductance and microvascular dimensions, 3) the post-sympathectomy functional changes in receptor sensitivity, and 4) the identification of the receptor subtype having the maximal influence on functional supersensitivity. Together, these experiments will characterize the relationship between the adrenergic system and sympathectomy-related, cold-evoked vascular responses.

日常生活活动改变，工作效率下降

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Effect of cooling on cutaneous microvascular adrenoceptors in vivo in the rabbit ear.

冷却对兔耳体内皮肤微血管肾上腺素受体的影响。

DOI：
10.1002/jor.1100160206
发表时间：
1998
期刊：
Journal of orthopaedic research : official publication of the Orthopaedic Research Society.
影响因子：
0
作者：
Li,Z;Koman,LA;Rosencrance,E;Pollock,DC;Smith,BP;Strandhoy,JW;Smith,TL
通讯作者：
Smith,TL

Acute effects of periarterial sympathectomy on the cutaneous microcirculation.

动脉周围交感神经切除术对皮肤微循环的急性影响。

DOI：
10.1002/jor.1100150313
发表时间：
1997
期刊：
Journal of orthopaedic research : official publication of the Orthopaedic Research Society.
影响因子：
0
作者：
Pollock,DC;Li,Z;Rosencrance,E;Krome,J;Koman,LA;Smith,TL
通讯作者：
Smith,TL

Alpha adrenoceptors in the rabbit ear thermoregulatory microcirculation.

兔耳温度调节微循环中的α肾上腺素受体。