Site-specific changes in zinc levels in the epididymis of rats exposed to ionizing radiation

The epididymis is an accessory sex organ that plays an important role in sperm maturation and storage. Trace elements, such as copper (Cu), manganese (Mn), zinc (Zn) and selenium (Se), have a pivotal role in spermatogenesis. We studied the effects of radiation on trace element levels in the epididymis in male Wistar rats using inductively coupled plasma–mass spectrometry (ICP–MS). We determined trace element concentration in segment-dissected specimens and used micro-PIXE analysis to determine Zn in epididymal sections in situ.Zn concentrations in the caput and cauda epididymis of control rats were 37.7 ± 6.5 μg/g wet weight and 18.7 ± 4.1 μg/g wet weight, respectively. At 6 h after irradiation at a single dose of 5Gy, the Zn level decreased by 33% in the caput epididymis, whereas the level did not change in the cauda segment. Similar results were obtained for Se, but not both Cu and Mn. PIXE spot analysis revealed that Zn in the lumen of the epididymal tubules decreased after irradiation.