SYNERGETIC INTERPRETATION OF PATTERNED VASOMOTOR ACTIVITY IN MICROVASCULAR PERFUSION - DISCRETE EFFECTS OF MYOGENIC AND NEUROGENIC VASOCONSTRICTION AS WELL AS ARTERIAL AND VENOUS-PRESSURE FLUCTUATIONS

Synergetic concepts allow to identify emergent coordination phenomena between interacting physiological systems, for example between the cut aneous microcirculation, the sympathetic nervous system and the cardia c and pulmonary systems, The temporal patterns (oscillations of variou s frequencies) that are found in the data obtained with laser-Doppler anemometers (LDA; e.g. Periflux 2 used in the study) can be investigat ed by simultaneous recording of photoplethysmographic data obtained in the identical region of interest, as well as in cutaneous regions tre ated with vasoparalytic procedures which permit to record the dynamics of the arterial system, These strategies were applied to studies in t he cutaneous microcirculation (volar side of the index fingers) as wel l as to mucosal microcirculation (maxillar gingiva) in healthy subject s and in patients suffering from autonomic dysfunction (cutaneous micr ocirculation) or gingivitis, By this procedure, it could be corroborat ed that - contrary to popular notions - the temporal fluctuations in t he LDA records do not necessarily reflect myogenic vasomotion, but can have multiple causes. In a confirming recent study [Schmid-Schonbein et al., J auton Nerv Syst, 57, 136-140, 1996], we have demonstrated th at the LDA fluctuations under conditions of normal ambient temperature and hand position most likely reflect neurogenic vasoconstriction. Un der exceptional conditions, different patterns emerge, Prolonged expos ure to ambient temperature (18 degrees C) leads to marked vasoconstric tion, with occasional vasodilator escape ('miniature hunting reaction' ), Normal subjects under gravitational load and in warm environment (2 8 degrees C ambient) silence their neurogenetic vasoconstriction react ions, which allows sinusoidal vasomotion to dominate. A similar phenom enon is seen in neuropathic patients at 21-24 degrees C (presumably du e to structural defects), Fluctuations in LDA signal taken from the he althy gingiva are entrained to arterial, those taken from inflamed gin giva to respiratory activity, The theory and practice of nonlinear ana lysis is discussed, and data compression procedures allowing to portra y characteristic temporal patterns for future diagnostic procedures ar e presented.