Renewal of Leydig cells in the neonatal and adult monkey: a radioautographic study

Abstract
The populations of interstital cells in the testis of three 2-3 month old monkeys and of three 5-6 years old adults (Macaca fascicularis) were analyzed: percentage, mitotic index and labelling index after 3H-thymidine injection. In the young monkey and the adult well differentiated Leydig cells incorporate the precursor as fibroblast-like cells. This demonstrates their ability of renewal.