Expression and distribution of laminin chains in the testis for patients with azoospermia

The aim of our study was to investigate the relationships between the expression of laminin in the testis and spermatogenesis, and the basement membrane (BM) of testicular tubules in fertile and infertile men. Testicular tissue samples were collected from the testes of 9 patients with obstructive azoospermia (OA), 9 patients with maturation arrest (MA), and 15 patients with Sertoli cell-only syndrome (SCO). In testicular tissue, laminin was identified by staining with polyclonal antibodies. Serum follicle-stimulating hormone (FSH), lutenizing hormone (LH), and testosterone were determined by chemiluminescence assays. In seminal plasma, laminin was estimated using a double-antibody enzyme immunoassay. BM thickness was significantly correlated with testicular tubule diameter (r = -0.49, P = .004) and FSH (r = 0.52, P = .008). The beta2 chain of laminin was most expressed on the inner BM of testicular tubules. The laminin index for the beta2 chain in SCO was significantly higher than in OA (P < .0001) and MA (P = .03). The mean seminal laminin levels in SCO were significantly lower than in OA (P < .001). We demonstrated that overabundance of the beta2 chain of laminin is associated with increased BM thickness and is possibly related to spermatogenic dysfunction.