POSSIBLE PRESENCE OF AN AMH-IMMUNO-LIKE PROTEIN IN THE INTERSTITIAL CELLS OF EUTOPIC SCROTAL TESTIS OF PREPUBERTAL UNILATERAL CRYPTORCHID SWINE

The anti-Müllerian hormone (AMH), a homodimeric cytokine of the transforming growth factor-β supe family is synt esi ed in t e gonads of all ve teb ate species examined to date (1). AMH plays crucial roles in sexual differentiation and gonadal functions of both sexes. In mammal males, AMH is expressed by the testis Sertoli cells, triggers the regression of the Müllerian ducts during the early fetal life, modulates the gonadal function during the postnatal life up to puberty, and has extra-gonadal effects on the hypothalamic-pituitary-gonadal axis (2). In mammals, circulating AMH appears to be entirely derived from the gonads and its concentrations have been used to assess several testicular pathologies (3) as in hemi-castrated unilateral cryptorchid horses (4). Since the possible role of AMH as an endocrine marker of cryptorchidism in boars is unexplored, the aim of this study was to investigate the gene and protein expression of AMH in testes of neonatal and prepubertal unilateral cryptorchid swine at different ages. Cryptorchid and contro-lateral normally descended testes of neonatal (8 days, n = 4) and prepubertal unilateral cryptorchid swine of different age (2, 3, and 5 months, n = 12) were used. Immunohistochemical investigation was performed using two different commercial polyclonal anti-AMH swine specific primary antibodies. Western blotting was performed using the same immunohistochemistry primary antibodies. AMH gene expression was evaluated by RT-PCR using primers designed on the specific mRNA sequence. Independently of the antibody used for immunohistochemistry, the Sertoli cells of all neonatal and prepubertal cryptorchid testes showed strong positive signals for AMH. By converse, positive signals progressively decreased in the Sertoli cells of contro-lateral, normally descended testes from neonatal to late prepubertal phase. Surprisingly, the interstitial cells of descended prepubertal testes showed an age-related increase of positive immunosignals for AMH. Western blotting data confirmed the specificity of the two antisera used for immunohistochemistry. AMH gene expression was observed in all testes. Even if our data need to be confirmed, we think that it is important to present such preliminary findings that suggest the possible presence of an AMH-immuno-like protein in the Leydig cells of normally descended testis of prepubertal unilateral cryptorchid swine. 1) Cimino I, et al. Nat Commun. 2016; 7:10055. 2) McLennan IS, Pankhurst MW. J Endocrinol 2015; 226:R45–R57. 3) Ball BA, et al. Theriogenology. 2008; 69:624-31. 4) Murase H, et al. J Equine Sci 2015; 26:15-20.