Effects of lead, cadmium, copper and zinc levels on the male reproductive function

Abstract

This study aimed to investigate the effects of heavy metals on measures of male fertility. One hundred and two infertile men with occupational exposure and thirty fertile men were included in this study. Blood and urinary levels of lead, cadmium, zinc and copper were measured by atomic absorption spectrophotometry. Semen parameters and a motile sperm organelle morphology examination were also performed. Measures of hormonal levels, oxidation–reduction potential, DNA fragmentation index and chromatin condensation were assessed for all participants. Heavy metals levels, oxidative stress and DNA quality were significantly higher in the infertile group compared to controls. FSH and testosterone levels were lower in the infertile group. A urinary cadmium level was positively associated with abnormal sperm morphology (r = .225, p < .05). Normal morphology was inversely correlated with the duration of the exposure (r = −.227, p = .022). The blood lead level was positively related to the level of testosterone (r = .223, p = .031). Cadmium and lead blood levels were positively correlated with the level of chromatin decondensation (r = .528, p < .001; r = .280, p = .017). Our study showed that occupational exposure to heavy metals is very harmful to reproductive health. DNA quality and oxidative stress investigations must be recommended for reprotoxic exposed patients prior to in vitro fertilisation treatment.

Melatonin modulates Nrf2 activity to protect porcine pre‐pubertal Sertoli cells from the abnormal H2O2 generation and reductive stress effects of cadmium

“…Therefore, the redox‐modulating function of MLT was investigated. MLT has been proposed to produce both direct and indirect (gene expression‐mediated) antioxidant effects, which could play a key role in preventing the pro‐oxidant effects of Cd and their damaging effect on testicular cells 33,54,55 . Our findings in porcine pre‐pubertal SCs confirm that Cd toxicity is associated with the induction of a pro‐oxidant environment by sustained production and release in the extracellular space of H 2 O 2 (Figure 1).…”

“…MLT has been proposed to produce both direct and indirect (gene expression-mediated) antioxidant effects, which could play a key role in preventing the pro-oxidant effects of Cd and their damaging effect on testicular cells. 33,54,55 Our findings in porcine pre-pubertal SCs confirm that Cd toxicity is associated with the induction of a pro-oxidant environment by sustained production and release in the extracellular space of H 2 O 2 (Figure 1). This type of response highlights the phagocyte-like phenotype of these cells and their capability to produce an oxidative burst to protect the testes from exogenous treats.…”

“…[24][25][26] Such specific toxicity is associated with indices of oxidative stress and DNA damage in sperm, and currently it represents an important health concern and an emerging risk factor for human male infertility. 54,55 In an effort to develop effective chemopreventive treatments against Cd toxicity, recent studies by Li et al 25 and Venditti et al 27 described the role of MLT in protecting the integrity of BTB in rat testes exposed to this metalloid, with proposed effects on autophagy pathway activation and function of SCs. 27 Considering these findings and the overall role of SCs as metronome of testicular homeostasis and spermatogenesis process, we herein investigated the effects of MLT in protecting SCs against Cd toxicity, with a focus on the redox-dependent mechanism of action of this hormonal substance.…”

“…Recent studies suggested that this hormonal substance may prevent Cd toxicity also in the mammalian testes 24–26 . Such specific toxicity is associated with indices of oxidative stress and DNA damage in sperm, and currently it represents an important health concern and an emerging risk factor for human male infertility 54,55 …”

Age-Related Decline of Male Fertility: Mitochondrial Dysfunction and the Antioxidant Interventions

“…This helps to maintain the semen quality and homeostasis of testicular environment [ 90 ]. Other studies also confirmed that the zinc concentration in seminal plasma of fertile men is significantly higher than that of infertile men [ 91 ]. Zinc’s antioxidant properties appear to be attributed to its ability to reduce production of hydrogen peroxide and hydroxyl radicals by antagonizing redox-active transition metals (such as iron and copper) [ 92 ].…”