Mechanisms of Cadmium-Induced Testicular Injury: A Risk to Male Fertility

Cadmium is a heavy toxic metal with unknown biological functions in the human body. Over time, cadmium accretion in the different visceral organs (liver, lungs, kidney, and testis) is said to impair the function of these organs, which is associated with a relatively long biological half-life and a very low rate of excretion. Recently studies have revealed that the testes are highly sensitive to cadmium. In this review, we discussed the adverse effect of cadmium on the development and biological functions of the testis. The Sertoli cells (SCs), seminiferous tubules, and Blood Testis Barrier are severely structurally damaged by cadmium, which results in sperm loss. The development and function of Leydig cells are hindered by cadmium, which also induces Leydig cell tumors. The testis's vascular system is severely disturbed by cadmium. Cadmium also perturbs the function of somatic cells and germ cells through epigenetic regulation, giving rise to infertile or sub-fertile males. In addition, we also summarized the other findings related to cadmium-induced oxidative toxicity, apoptotic toxicity, and autophagic toxicity, along with their possible mechanisms in the testicular tissue of different animal species. Consequently, cadmium represents a high-risk factor for male fertility.