Inhibins in the male G  ttingen miniature XXXX : Leydig cells are the predominant source of inhibin B.

@entity70591 @entity1707 @entity25086
The expression of inhibin subunits in the testes of the G  ttingen miniature @entity1707 was examined by in situ hybridization and immunohistochemistry. In addition, the major forms were determined by enzyme-linked immunosorbent assay (ELISA). Strong positive immunostaining for the @entity70591 was observed in Sertoli and late-stage germ cells, but it was weak in Leydig cells. However, Leydig cells showed strong positive staining for the betaA subunit, but Sertoli cells and spermatogonia showed a weak reaction. Strong positive immunostaining for the betaB subunit was observed in Leydig cells but spermatogonia showed weak staining for it. In contrast to the staining specificity of @entity70591 and betaA subunits, the betaB subunit did not exhibit positive staining in Sertoli cells. In situ hybridization revealed that although the a subunit mRNA signal was highly expressed in all cell types, the reaction appeared to be stronger in Sertoli cells and spermatogonia than in Leydig cells. betaA subunit mRNA expression was somewhat identical to that of the alpha subunit, however, germ cells showed a weak stain for it. A strong, positive mRNA signal for the betaB subunit was confined to Leydig cells and late-stage germ cells. ELISA results showed that concentrations of @entity25086 and inhibin pro-alphaC were high in the circulation and testes. In contrast, @entity70591 levels in both plasma and testes were undetectable. The present results strongly suggest that inhibin B is the major form of circulating inhibin and that Leydig cells are the predominant source of this dimeric inhibin in male G  ttingen miniature @entity1707 . Furthermore, the germ cells also appear to be an important source of circulating inhibins.
