MICROARCHITECTURE OF THE CAT TESTIS WITH SPECIAL REFERENCE TO LEYDIG-CELLS - A 3-DIMENSIONAL STUDY BY ALKALI MACERATION METHOD AND SCANNINGELECTRON-MICROSCOPY

Testes from adult cats were studied by means of parallel transmission and scanning electron microscopy (SEM) after NaOH digestion technique, which selectively removed connective tissues or cells. The testis is covered by a dense fibroconnective tunica albuginea that partially div ides the organ in lobules by sending septa into the parenchyma. The la mina propria of the seminiferous tubules consisted of one or two rows of cells. The interstitium was made up of randomly arranged collagen b undles. The most significant feature was the numerous Leydig cells ric h in lipid droplets and displaying epithelioid features. Following alk ali digestion and SEM these cells showed a cordlike arrangement. The c ords were formed by one or two closely apposed cells, in between which some labyrinthine or canalicular-like spaces were left that in some a reas opened in wide perivascular spaces. This particular arrangement o f Leydig cells and the labyrinthine intercellular spaces is very likel y designed to improve cell secretion of hormones, facilitating their t ransport into the blood, as well as the traffic of fluids and metaboli tes. The present techniques allowed the visualization of a real three- dimensional testicular microarchitecture and microtopography, not dete ctable with other methods. Such a study may help to better highlight t he testicular morphophysiology.