Identification, ontogeny, and regulation of an interleukin-6-like factor in the rat seminiferous tubule

Endocrinology. 1993 Jan;132(1):293-9. doi: 10.1210/endo.132.1.8380379.

Abstract

The present study's aims are to search for the presence of interleukin-6 bioactivity (IL-6) in medium conditioned by various testicular cell types and to investigate the cellular and hormonal regulation of testicular IL-6 production. Sertoli cells prepared from rats of increasing ages (20, 35, and 45 days) secreted IL-6 in vitro, whereas medium conditioned by pachytene spermatocytes, early spermatids, and peritubular cells showed no activity. Lipopolysaccharide (LPS) and latex beads, two known stimulators of monocyte/macrophage IL-6 production, markedly stimulated IL-6 secretion by Sertoli cells at all the ages investigated. Maximum levels of IL-6 were reached after 6 h of culture of Sertoli cells with LPS and after 24 h with latex beads. When Sertoli cells were cocultured with pachytene spermatocytes, early spermatids, or fractions containing residual bodies and cytoplasts from elongated spermatids, only the latter significantly stimulated IL-6 levels. Maximum levels of IL-6 were attained by adding 2 x 10(6) residual bodies to Sertoli cells; a significant increase in IL-6 secretion was seen after 6 h, and maximum levels were observed after 24 h. The levels of IL-6 varied throughout different stages of the seminiferous epithelium cycle; highest levels were observed in stages II-VI and lowest in stages VII-VIII. IL-6 bioactivities induced by LPS and residual bodies and cytoplasts from elongated spermatids could be totally neutralized with a specific monoclonal antibody at all of the ages studied. FSH, phorbol myristate acetate, and IL-1 alpha augmented Sertoli cell IL-6 secretion in a dose-dependent manner. Furthermore, FSH and (Bu)2cAMP differentially stimulated IL-6 secretion during the seminiferous epithelial cycle. It is concluded that the release of IL-6 from Sertoli cells is regulated by a complex interplay between residual bodies and humoral factors.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aging / metabolism
  • Animals
  • Bucladesine / pharmacology
  • Cells, Cultured
  • Follicle Stimulating Hormone / pharmacology
  • Interleukin-6 / metabolism*
  • Lipopolysaccharides / pharmacology
  • Male
  • Microspheres
  • Rats
  • Rats, Sprague-Dawley
  • Seminiferous Epithelium / physiology
  • Seminiferous Tubules / growth & development*
  • Seminiferous Tubules / metabolism
  • Sertoli Cells / metabolism*
  • Spermatids / metabolism
  • Spermatozoa / metabolism

Substances

  • Interleukin-6
  • Lipopolysaccharides
  • Bucladesine
  • Follicle Stimulating Hormone