Vasomotion in human skin before and after local heating recorded with laser Doppler flowmetry. A method for induction of vasomotion.

Rhythmical variations in blood cell flux in human skin have been studied using laser Doppler flowmetry. The fluctuations in blood cell flux could be divided into two different categories named alpha- and beta-oscillations with a median frequency of 6.8 min-1 and 1.5 min-1, respectively. The amplitude of beta-oscillations was approximately two to four times the amplitude of alpha-oscillations. Simultaneous registration from different skin regions showed periods with synchronous and non-synchronous fluctuations for both alpha- and beta-oscillations. alpha-oscillations were unchanged during local and ganglionic nerve blockade and were preserved in chronically sympathectomized tissue. In contrast, beta-oscillations disappeared completely after the three types of denervation. We suggest alpha-oscillations to be local non-neurogenic vasomotion and beta-oscillations to be a vascular reaction of pure neurogenic origin. A method for induction of regular amplified alpha-oscillations was discovered and evaluated. When heating the skin locally to 42 degrees C the blood cell flux increased and the pre-heating alpha- and beta-oscillations disappeared. During the post-heating period, amplified regular rhythmic alpha-oscillations appeared. At the end of the post-heating period beta-oscillations re-appeared.