Histological examination

Animals were sacrificed through neck dislocation and dissected to isolate the testis at the end of the study (day 30). The histological analysis of the testis was evaluated according to a previously described method [32]. The testis was washed with phosphate-buffered saline and then fixed in 10% formaldehyde for 24 h. The tissue samples were dehydrated in an alcohol solution by follow-up routine methods and embedded in paraffin. Five-micrometer-thick section was stained with hematoxylin–eosin and histologically analyzed using an Olympus BX51 microscope (Olympus Corporation, Inc., New York, NY, USA). The germinal epithelium thickness and the diameter of the seminiferous tubules were investigated with 400× magnification. The assessment of spermatogonia, spermatocyte, spermatid, and Leydig cells was quantified in ten random microscopic fields in the interstitial compartment located between the three tubules.