In vitro cytophotometry evaluation of gamma-radiation effects on human sperm cell by acridine orange staining

Effects of gamma-radiations on human sperm nuclei in vitro were studied by cytophotometrical quantification on fixed smears stained by acridine orange some of which had undergone heat-treatment. Following irradiations at different doses (0.0, 2.5, 5.0, 7.5 gy) using a cobalt source, changes in distribution of acridine orange fluorescences emitted by nuclei (total fluorescence greater than 515 nm versus green fluorescence = 525 nm) appeared to be dose-dependent. Heat-treatment of irradiated heads was confirmed to be a complementary procedure necessary for a good evaluation of the initial degree in chromatin compactness. Chromatin alterations related to changes in emitted fluorescence could be due to the initial fragility of the DNA-nucleoprotein complex. These preliminary results suggest that the normality of sperm chromatin could be used as a biologic dosimeter.