Aellig W H
Methods Find Exp Clin Pharmacol. 1985 Jun;7(6):321-4.
Direct effects of vasoactive substances on superficial human veins in vivo can be investigated by measuring changes in the diameter of a superficial vein at a standardized congestion pressure which reflect changes in venous tone before and after local infusion of the drugs. The diameter of a superficial hand vein is measured with the aid of a linear variable differential transformer mounted directly on the back of the hand. The central core of the transformer positioned over the summit of the vein moves simultaneously with changes in venous diameter and allows continuous recording of these alterations. A series of ergot alkaloids were investigated with this technique and found to elicit a direct constrictor action when infused locally. Studies on the mode of action of the venoconstrictor effects of ergot alkaloids suggest that they are mediated by stimulation of alpha- and 5-HT-receptors. Similarly, guanfacine, a centrally-acting antihypertensive drug, reduces venous compliance after direct local administration as a result of alpha-adrenoceptor stimulation. The venodilator effect of isoprenaline can be shown in veins preconstricted with noradrenaline, whereas with nitroglycerine, venodilatation is observed by local infusions in veins not preconstricted. This method is therefore useful for studying the direct effects of venoconstrictor and venodilator drugs in man. The technique can also be used to study interactions between different agents and thus to investigate the mode of action of drugs. Drugs can be infused locally at doses which do not elicit systemic effects.
血管活性物质对人体浅表静脉的直接作用可通过在标准化充血压力下测量浅表静脉直径的变化来研究，该变化反映了局部注入药物前后静脉张力的变化。借助直接安装在手背的线性可变差动变压器测量手部浅表静脉的直径。变压器的中心芯位于静脉顶部上方，随着静脉直径的变化同步移动，并允许连续记录这些变化。用该技术研究了一系列麦角生物碱，发现局部注入时会引发直接的收缩作用。对麦角生物碱静脉收缩作用的作用方式研究表明，它们是通过刺激α受体和5-羟色胺受体介导的。同样，胍法辛是一种中枢性抗高血压药物，直接局部给药后，由于α肾上腺素能受体刺激，静脉顺应性降低。异丙肾上腺素的静脉扩张作用可在预先用去甲肾上腺素收缩的静脉中显示，而硝酸甘油则通过在未预先收缩的静脉中局部注入观察到静脉扩张。因此，该方法对于研究血管收缩药和血管扩张药对人体的直接作用很有用。该技术还可用于研究不同药物之间的相互作用，从而研究药物的作用方式。药物可以以不引起全身作用的剂量局部注入。
