Cells of Leydig
(Posted on June 18, 2013 by David McMillin)
The cells of Leydig (also called Leydig cells) are interstitial cells found in the testicle (in males) and ovary (in females, although in much fewer numbers that males). The cells are polyhedral in shape, display a large prominent nucleus and produce testosterone, a male sex hormone.
Although the Cayce readings do not specifically mention "cells of Leydig" by name, preferring Leydig gland (or lyden gland), some people have identified the cells of Leydig as the Leydig gland as described by Cayce in his readings. Mature cells of Leydig do perform an endocrine function by secreting testosterone directly in the bloodstream. They are also located in the gonads of the reproductive system as specified in certain readings. The main problem is that at least one reading clearly describes the Leydig gland as a discrete anatomical entity that is normally about the size of a small pea. Another reading speaks of the gland putting pressure on adjacent nerves, which does not sound like the interstitial cells of Leydig.
At this point we are keeping an open mind and trying to uncover as much information as possible about all the possible options pertaining to the Leydig gland as described in the Cayce readings. It makes sense to begin with the discoveries of Dr. Leydig, and his earliest relevant discovery was probably in about 1850.
Discovery in 1850
Franz Leydig reported finding what are now called "cells of Leydig" in 1850 in a publication titled " Zur Anatomie der männlichen Geschlechtsorgane und Analdrüsen der Säugetiere. Zeitschrift für wissenschaftliche Zoologie." Click here for the entire document in German and pdf format. The following brief English translation from page 47 is a succinct description of the anatomy of the cells of Leydig as Dr. Leydig portrayed them:
Comparative studies of the testis resulted in the discovery of cells surrounding the seminiferous tubules, vessels, and nerves. These special cells are present in small numbers where they follow the course of the blood vessels, but increase in mass considerably when surrounding seminiferous tubules. These cells are lipoid in character; they can be colorless or can be stained yellowish, and they have light vesicular nuclei. (Leydig, 1850, p. 47)
Clearly, Leydig located these cells within the gonads, which is consistent with a portion of the readings' description. Thus, although Leydig nicely conveyed the anatomy of the cells of Leydig in this excerpt he didn't really address physiology (i.e., activity), which is emphasized in reading 281-53:
(Q) The leydig gland is the same as that we have called the lyden, and is located in the gonads.
(A) It is in and above, or the activity passes through the gonads. Lyden is the meaning – or the seal, see? while Leydig is the name of the individual who indicated this was the activity. You can call it either of these that you want to. (281-53)
So the question is whether there is any additional information in this document (or other writings by Leydig) that is relevant to the Cayce readings that discuss the Leydig gland and its physiological activity. In the resources below, the Christensen review provides a more modern, comprehensive treatment of the cells of Leydig that does address physiology (i.e., "activity"), but at a much later date than when Cayce gave the reading linking the name "Leydig" to the Lyden gland.
Leydig, F. (1850). Zur Anatomie der männlichen Geschlechtsorgane und Analdrüsen der Säugetiere. Zeitschrift für wissenschaftliche Zoologie. Bd. II., 1-57.
A History of Leydig Cell Research by A. Kent Christensen is an excellent review of Dr. Leydig's discovery and the major subsequent findings by modern research.