The Effect of Low-Level Lead Exposure on the Testicle Tissue and Hormone of Male Rabbits in Juvenile Stage

[Objective] To explore the effect of low-level lead exposure on the testicle tissue and hormone of male rabbits in juvenile stage.[Methods]Sixteen 45-day-old male New Zealand rabbits were randomly divided into control group and lead- exposed group with 8 in each group.Rabbits in the lead-exposed group were treated with 5 mg/kg day lead acetate in their forage for 6 weeks to establish low-level lead exposure animal model.The blood lead levels and the lead concentrations in testicle were determined by atomic absorption spectrometer (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS) respectively. Histopathology and uhra-mierestructure in testicle tissue were observed under light microscope and electron microscope.The levels of testosterone(T),luteinizing hormone(LH)and follicular stimulating hormone(FSH)in serum were analyzed by enzyme linked immunosorbent assay(ELISA).[Results]Compared with the control group,there were significant increase in blood lead levels and lead eaneentrations in testicle in the lead-exposed group(for blood lead levels:t=100.08,P0.01;for lead concentrations in testicle:t=21.76,P0.01),significant deerease in testicle wet weight(t=21.896,P0.01)and testicle wet weight coefficient(t=22.03,P0.01),as well as obvious decrease in the levels of T(t=13.151,P0.01)and LH in serum(t=6.673, P0.01).With light microscope and electron microscope,the following phenomena were manifestly observed:the population of spermatogenie cells and Leydig cells decreased,the shape and structure of spermatogenie cells and Sertoli eells distorted, endothelial cells degenerated,and the tight junction released.[Conclusion]For male rabbits in juvenile stage exposed to low- level lead,the blood-testieal-barrier was destroyed,spermatogenic cells,Sertoli eells and Leydig cells were remarkably damaged, and the levels of hormone decreased.