Inhibin‐α Immunohistochemical Expression in Mature and Immature Canine Sertoli and Leydig Cells

Abstract

Formalin-fixed, paraffin-embedded sections from 32 canine pairs of testes were immunohistochemically examined for Inhibin-α (INHα). Samples were subdivided into two groups (group 1, neonates; group 2, puppies and adults) and results statistically compared. Inhibin-α was significantly expressed only in Sertoli cells of neonatal testes, while in Leydig cells it was expressed without significant difference between groups. These results suggest that, in dogs, INHα expression switches from Sertoli to Leydig cells during testicular maturation and that, in adult, Leydig cells represent the main source of INHα.

Immunohistochemical insights into a hidden pathology: Canine cryptorchidism

“…Details of the primary antibodies used, target cells, source, antigen retrieval methods and dilutions are reported in Table 1. All the antibodies employed in the present study were already demonstrated as reactive on targeted canine tissues in previous studies [24,25,26,36,37].…”

“…Since immature aspects can involve both seminiferous tubules structure and spermatogenesis, we used either vimentin (VIM), cytokeratins (CKs), desmin (DES), anti-Müllerian hormone (AMH) and Inhibin-𝛼 (INH) for studying Sertoli cells, and placental alkaline phosphatase (PLAP) to examine germ cells. All these markers have been previously demonstrated in dogs [13,24,[25][26][27][28]. Except for VIM, which is still present in adult life [24], the other markers are specific to the foetal/neonatal period in dogs [24,28].…”

“…Immunohistochemistry is especially valuable for investigating testicular immaturity. Indeed, cellular markers that are distinctive of definite periods during testicular development have been explored both in humans [21][22][23] and dogs [24,[25][26][27][28]. Since immature aspects can involve both seminiferous tubules structure and spermatogenesis, we used either vimentin (VIM), cytokeratins (CKs), desmin (DES), anti-Müllerian hormone (AMH) and Inhibin-𝛼 (INH) for studying Sertoli cells, and placental alkaline phosphatase (PLAP) to examine germ cells.…”

“…CK and DES are Sertoli cells cytoskeletal markers whose expression characterize foetal but not adult life [28]. AMH and INH are hormonal markers expressed by Sertoli cells up to 45 days post-natal period in dogs [25,26]. Afterwards, INH continues to be produced by Leydig cells [24,27] while AMH can't be detected over 120 days from birth [25].…”

“…Afterwards, INH continues to be produced by Leydig cells [24,27] while AMH can't be detected over 120 days from birth [25]. CK, DES, AMH and INH re-expression in adult life is abnormal and indicates an immature phenotype of Sertoli cells [25,26] related both to atrophy [28] and Sertoli cell tumours development [24,29]. Concerning germ cells, in physiological condition PLAP is expressed in man [30] and dogs [28] only by gonocytes, that are precursors of germ cells evolving into spermatogonia before birth.…”