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ADVERSE EFFECTS OF INHALATION EXPOSURE TO TRICHLOROETHYLENE (TCE) ON MALE REPRODUCTION.
Xu, Hongbin1, Shoushtarian, Ali1, Weerachatyanukul, Wattana1, Tantibhedhyangkul, Julierut1, D'Amours, Dominic1, Leader, Arthur2, Wade, Mike 3, Vincent, Renaud3, Tanphaichitr, Nongnuj1,4, 1 2 3 4
ABSTRACT- Clinical data have suggested that a number of male mechanics and dry cleaners, with high levels of TCE inhalation are infertile. In order to better understand TCE's effects on male reproduction, characterization of semen parameters and sperm functions of mechanics attending our infertility clinic, as well as studies on the reproductive system of TCE inhaling mice, was performed. Among the ten patients studied, only two had semen with clear indication of no abnormality in fertilizing potentials as defined by WHO and our criteria on using the A23187-induced acrosome reaction to assign male fertility. Inhalation experiments were performed by exposing mice to air containing 1,000 ppm TCE for 6 hr per day, 5 days per week with inhalation period varying from 1, 2, and 4 weeks, while control mice were kept in the identical conditions but without TCE. There were no significant changes in parameters including body weight, testis and epididymis weight, and caudal epididymal sperm number and motility right after each TCE exposure regimen and after a 4-week release into a TCE-free atmosphere following 2-week-TCE inhalation. However, sperm-zona pellucida (ZP) binding was significantly decreased by approximately 55% in TCE-treated mice after 2-week-TCE inhalation, as compared to control mice. Interestingly, no changes were observed in sperm-ZP binding after a 4-week release into a TCE-free atmosphere following 2-week-TCE inhalation, indicating that TCE's adverse effects were reversed in the 4-week release period. This may be due to degradation or metabolism of TCE into a less toxic substance(s). In addition, cultured Sertoli cells from TCE-treated mice showed less spreading of their processes with incomplete flattening to the substratum, as compared to cultured Sertoli cells from control mice. The vimentin immunofluorescenct staining also showed irregular patterns, corroborating the morphological results. The production of both ABP and prosaposin, as revealed by indirect immunofluorescence, appeared to be slightly decreased in the Sertoli cell cultures of the TCE-treated mice. Collectively, these results suggested that TCE may have toxic effects on the sperm surface, which may result in decreased sperm ability to bind ZP, and on the Sertoli cell structure and functions, which may ultimately affect spermatogenesis.
KEY WORDS: trichloroethylene (TCE), male infertility, fertilization, reproductive toxicology