Abstract: The endoplasmic reticulum is a multifunctional organelle that participates in material transport and plays an important role in biological activities such as protein modification and processing,synthesis of lipids and steroid hormones,cellular stress,and maintenance of calcium homeostasis.When there is an excessive accumulation of misfolded or unfolded proteins on the endoplasmic reticulum,it can cause an endoplasmic reticulum stress response that cannot be regulated,leading to the initiation of cell apoptosis.Leydig cells are the primary site of testosterone synthesis,converting cholesterol into testosterone through a series of enzymes,which is crucial for maintaining animal reproductive performance.Recent studies have shown that during the process of testosterone synthesis in male animal Leydig cells,endoplasmic reticulum stress,and the unfolded protein response are often involved,leading to cell apoptosis through different signaling pathways and affecting testosterone synthesis.However,the specific mechanisms by endoplasmic reticulum stress influences testosterone synthesis remain unclear.The authors reviewed the effects and possible molecular mechanisms of endoplasmic reticulum stress mediated apoptosis pathways,oxidative damage,and calcium signaling pathways on testosterone synthesis in male animal Leydig cells,in order to provide new insights into improving testosterone synthesis by regulating endoplasmic reticulum stress.

Key words: endoplasmic reticulum stress; Leydig cells; testosterone; cell apoptosis