Androgen production is the primary function of testicular Leydig cells. Recently, Leydig cells of the human testis have been shown to possess, along with well developed smooth endoplasmic reticulum, cytoplasmic vesicles and storage granules similar to those found in neuroendocrine and nerve cells. Moreover, a series of nerve cell-specific substances has been detected in Leydig cells. However, little is known about the physiological role of these molecules in testicular function.
Biomedical Reviews 1997; 8: 111-117.