Immunodetection of X-ray damage markers in red bloods cells of fishes

A sensitive method for detection of mutagenic effect following X-rays in humans has been proposed by Gong et al (Health Ph.77,1999). They demonstrated that X-rays, lead to an increase in expression of transferrin receptor (CD71) and a decrease in expression of glycophorin A (GPA) on the membrane of mammalian erythrocytes, correlated with the received x-ray dose. Aim of this research is to reveal the occurrence of CD71 and GPA on torpedoes erythrocytes, after X-irradiation, to obtain a sensitive method for assessing X-ray water pollution. Benthonic Elasmobranchs such as torpedoes, subjected to different single doses of total-body X-ray (10-120 Gy) displayed severe anaemia and leucopoenia and in haemopoietic tissues, the injured cells showed vesiculation, disruption and dysplastic nuclear changes, such as nuclear fragmentation. Red blood cell recovery following autologous haemotransplantation was completed in 28 days, while white blood cell recovery was slower. (Pica et al.,Comp.Haematol.Int.10, 2000). Erythrocytes of Elasmobranchs, like in all non mammalian vertebrates, are complete cells that maintain both the nucleus and the other organelles in mature stages, and their mitochondria exhibited canonical functional respiratory chain (Pica et al., CBP 128, 2001). Methods: FACS evaluation have been performed on blood of 2 Torpedo marmorata and 3 T. ocellata before and after 90 Gy X irradiation (sublethal dose), after incubation with anti CD71 and anti GPA antibodies. Preliminary results displayed an increase of Fluorescence medium intensity (MFI) of both the markers and an increase in percentage of immunoreactive cells 7, 14 and 21 days after X-irradiation. Fluorescence microscope observations on smears of the same cells measured at FACS, confirmed an increase in number of CD71-immunoreactive RBCs. Observations on blood samples from specimens exposed to decreasing doses of X rays are still in progress.