The aim of this study was to evaluate the histochemical characteristics of the thickened inner acellular layer (IL) of the lamina propria specifically present in the human seminiferous tubules of testes showing impaired spermatogenesis.METHODS
Eighteen biopsies for the investigation of infertility and 10 orchiectomies for testicular cancer and cryptorchidism were used. Lectin staining [peanut agglutinin (PNA), Maackia amurensis (MAA), Sambuccus nigra (SNA)], PNA lectin staining with sialidase digestion, immunohistochemistry and binding assay of progesterone were performed and analysed quantitatively.RESULTS
The IL of the thickened lamina propria of the seminiferous tubules in the testes showed PNA lectin affinity and binding affinity for progesterone. Both affinities of MAA and SNA were in the IL of only fairly thickened lamina propria. Furthermore, a positive correlation was present between the thickness of the lamina propria and the accumulation of glycoconjugates showing PNA lectin affinity (r = 0.829, P < 0.001) or progesterone (r = 0.629, P < 0.001) in the IL. However, ILs show no immunoreactivities of progesterone receptor, androgen receptor or human serum albumin. Progesterone inhibited the binding affinity of PNA lectin to the IL (P < 0.001), but not the affinity to the spermatogenic cells. In addition, sialidase digestion increased the PNA affinity not in the IL but in the spermatogenic cells (P < 0.001).CONCLUSIONS
These results indicate that the IL of the thickened lamina propria always consists of glycoconjugates with PNA lectin affinity and possible binding affinity to progesterone. In addition, the glycoconjugates in the IL may be predictors of abnormal spermatogenesis in the testes of infertile patients.