Effect of lead bioaccumulation on testicular microanatomy

Abstract

Humans are exposed to a notable variety of toxicants including lead as a heavy metal resulting from occupations and through environmental accumulation as in the Lebanese coastal and freshwaters. It is well established that lead exposure in the workplace contributes to worker infertility and decreased reproductive efficiency. Several reports have reported the detrimental impact toxic effects on human male reproduction by subsiding libido, spermatogenesis, semen quality, hormonal production and regulation, and much more. The objectives of this study were to inspect the effects of lead chloride (PbCl2) within the male reproductive system specifically on testicular microanatomy and spermatogenesis. Among the study outcomes was lead localization inside the testes and its spermatogenic series. In this respect, twenty healthy sexually mature male mice (Swiss white albino) aged between 72 and 80 with an average body weight ranging between 29.5 ± 2.03 g and 35.9 ± 1.99 g were treated with 0, 6, or 12 ppm of PbCl2 in a highly controlled experiment and sacrificed at sequentially every 9 days indicating distinct stages of the spermatogenic cycle. The mice testes were collected for histological assessment to determine Johnson’s Testicular Biopsy score and Spermatogenic cell counts, and to localize Lead (Pb) accumulation in the reproductive tissues via laser scanning microscope (LSM). Study findings report a significant decline in Johnson’s score 5 | P a g e from 10 during the first 9 days (Week1) of exposure to a score of 4.17 ±1.147 at day 36 (W4) of lead exposure (p-value: 0.000). Deterioration testicular histopathology from each subgroup was additionally reported. Similarly, spermatogenic cell counts were decreasing with week progression. Highest cell counts were delineated during the first 9 days of exposure (Week 1) with an average of 335 cells with 0 ppm Pb dose, reaching an average of 25 cells during day 36 (Week 4) with 12ppm dosage. Lead (Pb) fluorescence increased with the intensified dose and period of Pbl2 exposure. Pb accumulated in almost all spermatogenic populations. It was detected in Leydig and Sertoli cells from the first week of exposure. Having altered all seminiferous tubule cells, lead contamination may potentially employ a significant impact on spermatogenesis and sperm fertilization capacity, and reproduction success.