Total Leydig cell volume and its estimation in dogs and in models of testis.

Abstract

AbstractThe total Leydig cell volume has been determined in 40 dog testes using a histometric point‐counting method. In preliminary experiments, the accuracy of the method has been established on specially prepared plasticine models of the testis. The point‐counting method has a mean error of ± 7% and the values obtained by it, when statistically analysed, are not significantly different from those determined by direct measurements (p > 10% ). Thus, work on the models has provided convincing experimental verification of the method.The Leydig cells constitute about 15% (14.2 to 17.1% ) of the testicular volume in dogs. In absolute terms, it comes out to be 1.56 ± 0.45 ml of Leydig cells per testis. Larger testes contain proportionally greater amount of Leydig cell tissue, the relationship being almost linear. Although very little data is available for comparison, and none perhaps for the dog, it appears from the present study that the total quantity of Leydig cells in this species is essentially the same as in man.Since it allows a reliable estimate of the total Leydig cell volume directly in milliliters per testis, the point‐counting method has proved to be much more useful than older methods which merely determined the proportion of Leydig cells in relation to some other testicular component.