[Noninvasive determination of viscoelastic properties of human finger arteries under various tonus conditions affecting vascular smooth muscle].

The amplitude of the volume pulse in relation to transmural pressure and the compliance as a viscoelastic property of the digital arteries were determined noninvasively in 9 male subjects (mean age 16 years). The amplitude of the volume pulse was measured impedance-plethysmographically and the amplitude of the pressure pulse sphygmomanometrically. The registration of the pulses was performed under different conditions (sitting-control), lying, 3-min forearm ischaemia, concentration-performance test, hyperventilation, 0.8 mg Nitrangin sublingual) to provoke different states of the vessel wall. The amplitude of the volume pulse under concentration-performance test (0.054 +/- 0.015 ml), hyperventilation (0.045 +/- 0.015 ml) and Nitrangin (0.142 +/- 0.034 ml) is significantly (p = 0.025) different from control (0.086 +/- 0.016 ml). The amplitude of the volume pulse and the compliance increase with decreasing transmural pressure.