A new technique for recording compliance of human hand veins. Commentary. Author's reply

1 A new technique for determining venous compliance at a standardized congestion pressure has been developed based on the optical method described by Nachev, Collier & Robinson (1971). It uses a linear variable differential transformer for a direct and continuous recording of venous compliance. 2 This method has been used to establish dose-response curves for the constrictor effects of noradrenaline, adrenaline, 5-hydroxytryptamine and dihydroergotamine after direct local infusion. 3 A parallel shift to the right of the noradrenaline dose-response curves was observed after local infusion of phentolamine, showing that the method can be used also to study interactions between agonists and antagonists on human veins in vivo. 4 The usefulness of this technique for investigating the effects of orally administered drugs has also been established. The venoconstrictor action of dihydroergotamine reached its maximum after 1.5 h and remained almost constant for the period of observation (8 h).