Seminal transforming growth factor-beta in normal and infertile men

Transforming growth factor-beta (TGF beta) is a cytokine with autocrine and paracrine action in the testis and potent immunoregulatory and anti-inflam matory activities, In the present study, we examined the concentration of l atent (acid-activatable) and free (active) TGF beta in seminal plasma from normal subjects (n = 23) and infertile (n = 40) patients, by using a TGF be ta specific immunoenzymological assay, and a bioassay (CCL64 cell line grow th inhibition) detecting any form of TGF beta, Free TGF beta 1 was present in normal subjects at a concentration (1.82 +/- 1.06 ng/ml) close to that k nown to give maximal stimulation in vitro. In pathological groups, the mean concentrations were not significantly different from the normal ones. Late nt TGF beta 1 was present in normal seminal plasma at a high concentration (92.4 +/- 29.2 ng/ml), In subjects with pathologies of both testis and geni tal apparatus, or with epididymal occlusion, mean latent TGF beta 1 concent rations were normal, whereas transferrin concentrations were lower. The con centrations found in the epididymal occlusion group indicate that TGF beta 1 is, for a large part, secreted by the genital tract. In the testicular pa thology group, TGF beta 1 concentrations were 130.7 +/- 61.2 ng/ml, a mean not statistically different from normal, although higher, No differences we re found between patients with high and normal blood plasma follicle stimul ating hormone, and this is consistent with the notion that most TGF beta 1 in seminal plasma is not of testicular origin. The TGF beta bioassay ensure d that immunologically detected TGF beta was present in a bioactive or bioa ctivatable form, Furthermore, the values found in normal and pathological s eminal plasmas were usually higher than those detected by the immunoassay, suggesting that other forms of TGF beta might be present, Together, the pre sent data show that very large amounts of TGF beta are present in human sem inal plasma. The TGF beta ligand assay in the seminal plasma appears to ind icate no differences between normal and infertile subjects.