Regional differences of vasodilatation and vasomotion response to local heating in human cutaneous microcirculation

The aim of this study was to evaluate the vasodilatation and vasomotion response to local heating in the cutaneous microcirculation of the ankle, dorsum of foot and forearm. Recently, it has been suggested that this response differs between the forearm and the leg.

Twenty-nine young healthy adults were recruited. They underwent measurement by laser Doppler flowmetry (LDF) in three sites of the body (ankle, dorsum of foot, forearm). Percentage change of the median flow of the skin before and after provocation and normalised perfusion flow to maximal dilation (cutaneous vascular conductance--CVC % Max) during short provocation test were monitored. Spectral analysis of laser Doppler flowmetry signals was performed using the fast Fourier transform algorithm.

Significant differences were found in CVC % Max between ankle/dorsum (45.18±6.38% Max vs. 51.24±6.87% Max, respectively; p<0.05) and between ankle/forearm (45.18±6.38% Max vs. 54.49±5.37% Max, respectively; p<0.05). Percentage change of flux after provocation has revealed significant differences between ankle/dorsum (394.1±204.5% vs. 577.4±273.5%, respectively; p<0.05) and ankle/forearm (394.1±204.5% vs. 637.1±324.7%, respectively; p<0.05). Total spectral activity of vasomotion has differed between ankle/dorsum and ankle/forearm: 69.59 [49.58-96.04] vs. 93.01 [73.15-121.8] (p<0.05) and 69.59 [49.58-96.04] vs. 107.5 [80.55-155.8] (p<0.05), respectively.

Cutaneous microcirculation exhibits regional differences. Significant variability of function between ankle and dorsum of foot suggests that leg microcirculation is not uniform.