Krogstad A L, Elam M, Karlsson T, Wallin B G
Department of Clinical Neuroscience, Sahlgren University Hospital, Göteborg, Sweden.
J Auton Nerv Syst. 1995 Jun 25;53(2-3):215-22. doi: 10.1016/0165-1838(94)00178-m.
The reflex changes in skin blood flow which occur in response to various non-thermal stimuli (e.g., deep inspiratory gasps, arousing or painful stimuli, emotional stress) are profoundly influenced by the thermoregulatory state. The aim of the present study was to evaluate the involvement of arteriovenous anastomoses in the thermoregulatory modulation of skin vasomotor reflexes elicited by painful intraneural electrical stimulation and emotional stress (forced arithmetics), respectively. Vasomotor responses were recorded with laser Doppler flowmeters (LDF) placed on glabrous skin containing arteriovenous anastomoses (3rd finger and thenar eminence) and hairy skin which lack them (dorsal side of the first metacarpal bone). In some experiments, a laser Doppler flowmeter emitting laser light of two different wavelengths (infrared and green light) into the same skin site was used to record skin perfusion at different depths of glabrous skin on the thenar eminence. 40 subjects were investigated, both in the cold state (finger skin temperatures below 25 degrees C) and after subsequent warming (finger skin temperatures above 30 degrees C). Thermoregulatory modulation of electrical stimulation- or stress-induced vasomotor reflexes occurred both in glabrous and hairy skin, but hairy skin differed from glabrous skin by showing no significant vasoconstrictions. Relative perfusion changes were most marked in laser Doppler flowmeter recordings using the deeper penetrating infrared light. The results suggest that arteriovenous anastomoses are major contributors to the vasoconstrictor component of vasomotor reflexes in glabrous skin of warm subjects. The reflex increase in perfusion, on the other hand, which occurs in both glabrous and hairy skin of cold subjects may be mediated by resistance vessels.
皮肤血流的反射性变化是对各种非热刺激（如深吸气、唤醒或疼痛刺激、情绪应激）作出的反应，它受到体温调节状态的深刻影响。本研究的目的是分别评估动静脉吻合在由疼痛性神经内电刺激和情绪应激（心算）引发的皮肤血管运动反射的体温调节调节中的作用。使用激光多普勒血流仪（LDF）记录血管运动反应，该血流仪放置在含有动静脉吻合的无毛皮肤（第三指和鱼际隆起）和缺乏动静脉吻合的有毛皮肤（第一掌骨背侧）上。在一些实验中，使用向同一皮肤部位发射两种不同波长（红外光和绿光）激光的激光多普勒血流仪记录鱼际隆起处无毛皮肤不同深度的皮肤灌注情况。对40名受试者进行了研究，分别在寒冷状态（手指皮肤温度低于25摄氏度）和随后变暖后（手指皮肤温度高于30摄氏度）进行。电刺激或应激诱导的血管运动反射的体温调节调节在无毛皮肤和有毛皮肤中均有发生，但有毛皮肤与无毛皮肤的不同之处在于未显示出明显的血管收缩。在使用穿透性更强的红外光的激光多普勒血流仪记录中，相对灌注变化最为明显。结果表明，动静脉吻合是温暖受试者无毛皮肤血管运动反射血管收缩成分的主要贡献者。另一方面，寒冷受试者的无毛皮肤和有毛皮肤中均出现的灌注反射性增加可能由阻力血管介导。
