Dielectric relaxation of a protein-water system in atherosclerotic artery wall.

Measurements of the dielectric properties of healthy and atherosclerotic human artery tissues were made in the frequency range of 100 Hz-100 kHz and temperatures from 22 to 260 degrees C. The temperature dependencies of the dielectric parameters for healthy tissues reveal distinctively the temperature ranges corresponding to the release of water up to 200 degrees C and the decomposition processes of elastin and collagen, above this temperature. The influence of atherosclerosis on the dielectric properties of artery tissues is significant in the whole temperature range. The relative permittivity for atherosclerotic tissues at the same temperature is much lower than for the healthy tissues. This suggests, that the polarization in atherosclerotic tissues due to protons hopping between a smaller number of sites than in healthy tissues, as a results of the thermal degradation of collagen-water. The data obtained above 200 degrees C indicate that the atherosclerosis induces the higher physico-chemical changes in the collagen when compared to elastin.