Dielectric properties of healthy and diabetic alloxan-induced lenses in rabbits

The dielectric properties of the eye lens were studied for healthy and alloxane-induced diabetic rabbits in the frequency range from 500 Hz to 100 kHz electric field and temperatures from 25 to 50 degrees C. In the full temperature range, the average relative permittivity and dielectric loss values for a healthy lens are lower than those recorded for diabetic tissue. Dielectric relaxation of polar amino acids on the alpha-crystallin surface with a characteristic frequency of 7 kHz in the range of 25-50 degrees C for healthy and diabetic samples is accompanied by the activation energy of proton conductivity with an average values of 33 and 39 kJ mol(-1), respectively. The permittivity decrement, which characterizes the size of the dielectric dispersion with a central relaxation time of 0.023 ms for a diabetic sample, is more than twice as high as for a healthy sample. Measurements on the rabbit eye lens were carried out at ambient temperature above and below the physiological range, since these conditions provide an appropriate pattern of dielectric behavior for the diagnosis of clinical dysfunction of the human lens. (C) 2020 The Author. Published by Elsevier B.V.