LASER-DOPPLER FLOWMETRY FREQUENCY-ANALYSI S OF PHYSIOLOGICAL AND PHARMACOLOGICALLY STIMULATED NASAL FLOW MOTION

The term ''flow motion'' stands for the phenomenon of spontaneous and autonomous rhythmic variations of the contractile state of the smooth muscles of small dermal vessels. There also have been a few observatio ns of variations in the microcirculation of the mucosa, but they have not been evaluated in detail to date. The aims of this study were to d evelop a method for investigation flow motion, especially in the nasal mucosa; to compare nasal flow motion to that of other skin and mucosa l areas; to evaluate the influence of normal saline solution, as well as a sympathomimetic agent and histamine on flow motion. The microcirc ulation of the nasal mucosa of 40 healthy volunteers was measured unde r standardized conditions. In a first series of investigations, the mi crocirculations of the forehead, lobule of the ear, nose and oral muco sa were compared. In the second series, the microcirculation of the na sal mucosa was measured with laser-Doppler flowmetry before and after provocation with 0.9% saline solution, 0.25 mg oxymetazoline hydrochlo ride as sympathicomimetic preparation and 0.085 mg histamine in 0.5 ml of 0.9% saline solution. Evaluation of the data included signal analy sis of the microcirculatory variations using fast-Fourier transformati on and its changes before and after the pharmacological stimulations. Distribution of the power spectra showed that the nasal mucosa was sig nificantly different from that of the skin of the forehead and the ear . Oxymetazoline hydrochloride led to a clear increase and histamine to a significant reduction in the frequencies of the flow motion. The re sults of this study demonstrated that nasal flow motion could be detec ted and evaluated with laser-Doppler flowmetry and a special analysis of the data recorded. Specific patterns of the flow motion frequencies could be detected in the nasal mucosa that were distinctive from thos e of the skin. The pattern of the flow motion frequencies reacted very sensitively to the pharmacological provocations used.