Photosensibilization with Endogenous Riboflavin of the Isolated Mechanoreceptor Neuron and Satellite Glial Cells of the Crayfish <Emphasis Type="Italic">Astacus leptodactilus</Emphasis>

The photodynamic effect of the exogenous riboflavin on the mechanoreceptor neuron and satellite glial cells was studied in the isolated stretch receptor of the river crayfish. It was shown that the photodynamic action of exogenous riboflavin produced lesion of the cytoplasmic membrane and irreversible cessation of the neuron impulse activity, disturbance of integrity of the plasma membrane of glial cells, and development of necrotic processes in them. It also induces apoptosis of the glial cells. A disturbance of bioenergetic processes in the neuron and development of apoptosis in the glial cells was observed with a 4-h delay after the photoinduced cessation of the neuron impulsation. Riboflavin is known to be a photosensitizer of the first kind, which generates superoxide-anion during illumination. Its photodynamic effect on the neuron was essentially lower than the photodynamic effect of the earlier studied photosensitizers of the second kind—porphyrines, chlorines, and phthalocyanines. They produced the cell lesions that did not developed cessation of impulsation, as this took place in the case of photosensitizers of the first kind.__________Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 41, No. 3, 2005, pp. 259–265.Original Russian Text Copyright © 2005 by Dergacheva, Kolosov, Uzdensky.