Morphological characteristics of mastocytes in the infertile human testicle]

Mast cells, basophilic elements of the connective tissue, have been studied in numerous researches carried out both in man and animals. Previous studies showed that mast cells have been found in increased number in testis affected by pathology. In the present research morphologic characteristics of the mast cells in human infertile testis have been studied. Testicular biopsies obtained from 49 subjects, aged from 21 to 61 years, have been treated according to the current techniques for transmission electron microscopy. Results showed that it is possible to distinguish at least two types of mast cells: 1) "Interstitial" mast cells, large, round shaped, with great content of large characteristic granules, in relation with the loose connective tissue surrounding capillary vessels and Leydig cells; 2) "Peritubular" mast cells, flattened and relatively poor in granules, trapped in the conspicuous peritubular collagenic layers. These two types of mast cells differ from one another as concerns not only localization, but also general morphological characteristics and number and ultrastructure of cytoplasmic granules. Probably it is possible to establish a relationship between peritubular mast cells trapping and the increased deposition of fibrous connective tissue in the peritubular layers; such a deposition characterizes a lot of testicular pathologies.