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.
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.