The evaluation of microvascular tone was based on the amplitude responses of the LDF signal fluctuations in the appropriate frequency range in the dorsal skin of the rats during a thermal test (at 42 °C).  The increasing fluctuation amplitudes diminished in the endothelial frequency range in response to the thermal test and this was accompanied by abnormal NO levels in plasma of the diabetic groups as compared with healthy rats.  B. Dorsal skin LDF signals of a healthy rat during the thermal stimuli test. 
THERM