Molecular identity, expression and functional analysis of interleukin-1alpha and its isoforms in rat testis

Asian J Androl. 2004 Jun;6(2):149-53.


Interleukin-1alpha (IL-1alpha) is a proinflammatory cytokine that has also been found to act as a paracrine mediator involved in the regulation of testicular functions. The present review provides an overview of the role of IL-1alpha in testicular physiology. Bioactive IL-1alpha isolated from adult rat testis was found to consist of three distinct immunoreactive protein species with apparent sizes of 45, 24 and 19 kDa. These isoforms showed bioactivity in a thymocyte proliferation and steroidogenesis assays with different biopotencies. The background of the molecular heterogeneity and processing, secretion and regulation of the isoforms of testicular IL-1alpha are discussed. All three isoforms have been found to be secreted into the testis tubular lumen and interstitial space. We have provided evidence that IL-1alpha is a paracrine factor that may be of importance in, e.g., the regulation of Leydig cell steroidogenesis. Pathophysiologically, testicular IL-1alpha may contribute to testicular relapse of acute lymphocytic leukemia in boys.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Gene Expression Regulation / physiology*
  • Inflammation / pathology
  • Interleukin-1 / biosynthesis*
  • Interleukin-1 / chemistry
  • Interleukin-1 / genetics
  • Male
  • Protein Isoforms / biosynthesis
  • Protein Isoforms / chemistry
  • Protein Isoforms / genetics
  • Rats
  • Spermatogenesis / physiology
  • Steroids / biosynthesis
  • Testis / cytology
  • Testis / metabolism*


  • Interleukin-1
  • Protein Isoforms
  • Steroids