Morphological and histochemical characteristics of the lamina propria in scrotal and abdominal testes from postpubertal boars: correlation with the appearance of the seminiferous epithelium

This study was undertaken to investigate the morphological characteristics and lectin affinity of the testicular lamina propria in healthy boars and i n unilateral and bilateral abdominal cryptorchid boars. The lamina propria of scrotal testes from healthy boars and unilateral cryptorchid boars was c onstituted by an innermost noncellular layer, the basal lamina, and by 2 la yers of peritubular cells, each separated by a fibrous layer. The noncellul ar layers contained collagen fibres and glycoconjugates with abundant N-ace tylgalactosamine, galactose, fucose, N-acetylglucosamine and neuraminic aci d residues. The inner peritubular cell layer was composed of myoid cells, t he outer layer of fibroblasts. In the abdominal testes of unilateral and bi lateral cryptorchid boars, the lamina propria of nondegenerating and degene rating seminiferous tubules appeared thickened due to an increased content of collagen fibres and glycoconjugates. Glycoconjugates showed decreased am ounts of fucose, neuraminic acid and galactose, and increased amounts of N- acetylglucosamine residues. The basal lamina formed infoldings toward the s eminiferous epithelium and contained small cells. Both inner and outer peri tubular cells were fibroblasts of immature appearance. In degenerated semin iferous tubules of bilateral cryptorchid boars, the lamina propria was comp osed of a thickened and collagenised basal lamina, without peritubular cell s and with a low content of glycoconjugates. In scrotal testes, therefore, the lamina propria was implicated in tubular contractility and in mediating the communication and the substrate diffusion between seminiferous tubules and interstitial tissue. Cryptorchidism induced morphological and histoche mical alterations in the lamina propria of abdominal testes, which may be l inked to evidence from other studies of lack of tubular contractility and d efective cell-cell communication and substrate diffusion. The severity of t hese anomalies correlated with the severity of Sertoli cell alterations.