Mechanisms of the reprotoxic effect of lead: A literature review

Abstract

Introduction: The demographic situation in the Russian Federation over the past decades is noted for a low birth rate. According to the State Report by the Federal Service for Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor), in 2023, 75.4 million Russian people experienced combined exposure to multiple chemicals. Chemical exposure, particularly that to lead as an occupational and environmental risk factor, has a significant impact on the human reproductive system, starting from childhood. Objective: To search, summarize, and systematize published data on adverse effects of lead on the reproductive system as a basis for further development of therapeutic and preventive measures. Materials and methods: The sources for the bibliography search were the PubMed search engine, the Scopus abstract and citation database of peer-reviewed scientific literature, the eLibrary and CyberLeninka Russian electronic scientific libraries. The search was conducted among Russian and English-language publications issued in 2004–2024. Of over 500 articles screened, 36 full-text publications describing the results of epidemiological studies of lead exposure and its adverse effects on the reproductive system of laboratory animals and/or humans were selected for this review, of which 23 articles were published within the past 5 years. Results: The most frequent effects observed in a large number of studies assessing reproductive toxicity of lead include a change in the weight of the reproductive organs, disruption of their histological structure, cytotoxic effects on spermatozoa, their motility, viability, and integrity, the presence of abnormalities, as well as changes in the level of hormones in tissues and blood serum, activity and amount of enzymes associated with the reproductive system. The effect of lead on the reproductive system is inevitably accompanied by a change in the expression of genes responsible for regulation of inflammatory processes, activation or inhibition of apoptosis, antioxidant protection, regulation of the function of enzyme systems and hormonal changes. Conclusion: Further study of lead effects on the reproductive system will help reveal mechanisms of toxicity, which can subsequently be considered “critical points” for preventive health and therapeutic measures to be focused on.