Keywords: micronucleus assay, octreotate, somatostatin, human lymphocyte, 131I, 177Lu, DNA damage, genotoxic evaluation, low radiation, cytogenetic effect, blood cells, radioactive concentrations, binucleated cells
Genotoxic evaluation of octreotate labelled with 131I and 177Lu in human peripheral lymphocytes in vitro by micronucleus assay
octreotate has been used for cancer diagnosis and therapy because of its high affinity to somatostatin subtype receptors sstr2 and sstr5. The aim of this study was to evaluate the cytogenetic effect of radio-labelled octreotate in blood cells in vitro, using the cytokinesis-block micronucleus assay. Blood samples of healthy donors were exposed to different activities of octreotate labelled with 131I (n = 3) and 177Lu (n = 3), where radioactive concentration ranged from 600 to 5600 kBq/mL. The cells were cultivated according to criteria adopted by the IAEA (Vienna). The results showed a positive correlation between radioactive concentrations (X) and the frequency of binucleated cells with micronuclei (Y) (P 0.05). The linear equations were similar: for the 131I labelled, Y = (1.634 ? 0.236) = (0.912 ? 0.137) 10?3 X and for the 177Lu labelled, Y = (1.715 ? 0.342) = (0.743 ? 0.135) 10?3 X.