The regenerative capacity of testicular interstitial tissue : A recurrent pattern of experimental destruction and regeneration of rat Leydig cells.

A single intraperitoneal injection of ethane dimethanesulphonate (EDS) destroys all Leydig cells in the adult rat testis but 1-2 weeks later new foetal-type Leydig cells begin to regenerate within the interstitial tissue. A further EDS treatment at 4 weeks failed to kill the new population of foetal-type Leydig cells. Between 10-20 weeks, the new Leydig cells exhibited the characteristics of adult-type Leydig cells. These cells responded to another EDS treatment by exhibiting a second phase of complete degeneration followed by regeneration of a foetal-type and subsequently an adult-type cell population. The results indicate that the testis retains the ability to replenish its supply of Leydig cells despite successive phases of total degradation of Leydig cells.