Testis: Leydig Cell – Male Reproductive System

00:01 The Leydig cell is a cell, as I mentioned earlier, that sits in the interstitial space. It’s more commonly now called the interstitial cell of the testis. It produces testosterone. In this slide, if you look at the right-hand side, the histological section, Leydig cells sit in that interstitial compartment, and they’re stained very eosinophilic here. They have a nice rounded central nucleus.

00:36 Sometimes when you see them, they have little tiny droplets inside them. They represent lipid droplets, stores of cholesterol, because in the diagram on the left hand side, and I’m not going to go through all the process, the production of testosterone commences from these cholesterol stores inside the cell. Testosterone is needed in a number of stages in the life of the male. It’s needed in the embryo as part of the stimulation and initiation of sexual development and development of the sexual characteristics, the male organs in the embryo. It then goes through a dormant stage. And if you looked at sections of testis later on during the fetal development and even the early child, they appear just as, look like fibroblasts. They’re not making testosterone. They only start to make testosterone at puberty, in response to stimulation from the gonadotropins LH. And then, they secrete testosterone which is needed to initiate spermatogenesis and initiate the development or the final development and secretory activity of the accessory glands I’m going to describe in another lecture. And they’re also responsible for developing and maintaining sexual characteristics from puberty and beyond. And in the adult, they continue to be important to maintain the process of spermatogenesis and the maintainence of the accessory sex glands.