evaluating the role of silver nanoparticles on acrosomal reaction and spermatogenic cells in rat

background: nanoparticles have wide range of application while there are some reports regarding their probable effects on male reproductive system and spermatozoa. objective:  the aim of this study was to evaluate the effect of different doses of silver nanoparticles (agnps) (70nm) on acrosome of rat spermatozoa and number of spermatogenic cells. materials and methods:  in this experimental study, in experimental group, 32 male wistar rats (8 rats/group) received oral feeding agnps every 12 hr in one spermatogenesis period (48 days) by means of gavages in 25, 50 , 100 and 200 mg/kg concentration (experimental groups 1-4, respectively). the control group (8 rats) was treated on schedule with distilled water. spermatozoa were stained by triple staining protocol for acrosome reaction. histological evaluation on testis sections was performed using tissue processing and hematoxylin-eosin (h&e;) staining. results:  there was significant difference between the control group and the experimental group 1 for acrosome reaction (11.00±0.00 and 24.25±3.68, respectively, p=0.01). there was only significant reduction in spermatogonia cells in experimental group 4. experimental groups 2, 3 and 4 showed a significant reduction in the number of primary spermatocytes and spermatids as well as spermatozoa. but there were no significant differences between different groups for sertoli cell number and seminiferous tubule diameter. conclusion:  it seems that ag nps have acute and significant effects on spermatogenesis and number of spermatogenic cells and also on acrosome reaction in sperm cells. more experimental investigations are necessary to elucidate better conclusion regarding the safety of nanoparticles on male reproduction system.