Saumet J L, Abraham P, Jardel A
Laboratoire de Physiologie, Faculté de Médecine, Angers cedex, 49045, France.
Microvasc Res. 1998 Nov;56(3):212-7. doi: 10.1006/mvre.1998.2099.
Local warming alone induces a cutaneous vasodilation considered as maximal. The argument that local warming generates a maximum flow is being tested by vasodilation with alternate approaches to see if a greater vasodilation is possible: blockade of the release of transmitters from the adrenergic nerve endings with bretylium tosylate or direct pharmacological action on vascular smooth muscle using sodium nitroprusside. Nine healthy subjects participated in two experiments in which SkBF was measured simultaneously by laser Doppler flowmetry on the dorsal aspects of both hands. In the first protocol the vasodilator effects of 20 min of local warming at 44 degreesC were measured on one hand and the effects of iontophoresis of sodium nitroprusside on the other. The second protocol was like the first except that iontophoresis of bretylium tosylate instead of sodium nitroprusside was performed. Local warming induced an increase of SkBF from 17.6 +/- 4.4 to 140.2 +/- 33.2 AU (P < 0.01) while it rose from 16.7 +/- 4.0 to 114.7 +/- 11.0 AU (P < 0.001) during sodium nitroprusside iontophoresis. During the second protocol local warming induced an increase of SkBF from 14.9 +/- 2.1 to 117.7 +/- 25.4 AU (P < 0.01) while it rose from 19.6 +/- 2.6 to 120.5 +/- 11.3 AU (P < 0.001) during bretylium iontophoresis. However, in both experiments, the increase of SkBF attained during iontophoresis did not differ significantly from the increase achieved by local warming. We conclude that the effects of iontophoresis of sodium nitroprusside or of bretylium produce a cutaneous vasodilation as high as a local warming on the dorsal aspect of the hand.
仅局部升温就会引起被认为是最大程度的皮肤血管舒张。局部升温是否能产生最大血流量这一论点，正通过其他血管舒张方法进行验证，以探究是否有可能实现更大程度的血管舒张：用溴苄铵阻断肾上腺素能神经末梢递质的释放，或使用硝普钠对血管平滑肌进行直接药理作用。九名健康受试者参与了两项实验，通过激光多普勒血流仪同时测量双手背部的皮肤血流量（SkBF）。在第一个方案中，一只手测量44摄氏度下20分钟局部升温的血管舒张作用，另一只手测量硝普钠离子导入的作用。第二个方案与第一个类似，只是进行的是溴苄铵而非硝普钠的离子导入。局部升温使SkBF从17.6±4.4增加到140.2±33.2任意单位（P<0.01），而在硝普钠离子导入期间，SkBF从16.7±4.0增加到114.7±11.0任意单位（P<0.001）。在第二个方案中，局部升温使SkBF从14.9±2.1增加到117.7±25.4任意单位（P<0.01），而在溴苄铵离子导入期间，SkBF从19.6±2.6增加到120.5±11.3任意单位（P<0.001）。然而，在两项实验中，离子导入期间SkBF的增加与局部升温所实现的增加并无显著差异。我们得出结论，硝普钠或溴苄铵离子导入所产生的作用，会在手部背部引起与局部升温程度相同的皮肤血管舒张。
