Oxidative Stress in Rajidae electrocytes.

SCHMITD G, BARRERA F, PRADO FIGUEROA M.

Uguazú

Congreso; XL Annual Meeting ARGENTINE SOCIETY FOR BIOCHEMISTRY AND MOLECULAR BIOLOGY; 2004

SOCIEDAD ARGENTINA DE INVESTIGACIÓN BIOQUÍMICA Y BIOLOGÍA MOLECULAR

Psammobais extenta -Rajidae- is a weak electric fish with electric organs of myoblastic origin. Their electrocytes, which are cupshaped cells, have a large system of caveolae. We have studied the elemental composition in these electrocytes via electron probe X-ray microanalysis-Scanning Electron Microscopy. In the present study, the energy dispersive spectra showed an intracellular accumulation of oxygen and their relative semi-quantitative weight % (K3) was about 70. Nitrogen, Cu2+, Zn2+, and Al3+ were also present. In addition, P. extenta electrocytes exhibited a decomposition product of peroxidized polyunsaturated fatty acids such as malondialdehyde. Malondialdehyde production was estimated by the thiobarbituric acid (TBA) test on quantitative fractions. The distribution of malondialdehyde was detected in microsomes fraction after subcellular fractionation of the electric tissue. The relative specific activity (RSA) for microsomes was 4; nuclear fraction, large granules and final supernate 0.8, 0.9 and 0.6, respectively, with a recovery of % 105. These data are discussed in relation to electrocyte death.