Direct actions of cortisol, thyroxine and growth hormone on IGF-I mRNA expression in sea bream hepatocytes

Comp Biochem Physiol A Mol Integr Physiol. 2008 Dec;151(4):705-10. doi: 10.1016/j.cbpa.2008.08.023. Epub 2008 Aug 27.

Abstract

The present study aims to investigate potential regulatory effect of different growth-related hormones including growth hormone (GH), human insulin-like growth factor-I (hIGF-I), thyroxine (T(4)), triiodothyronine (T(3)) and cortisol, on insulin-like growth factor-I (IGF-I) mRNA expression of hepatocytes isolated from silver sea bream. By using real-time PCR, IGF-I mRNA expression profiles of hepatocytes in response to individual hormones were determined in vitro. Hepatocytes incubated with GH at concentrations of 10-1000 ng/mL showed significantly higher IGF-I expression, but the elevation was attenuated at high concentration of GH (1000 ng/mL). IGF-I expression remained unchanged in hepatocytes after incubation with hIGF-I. Hepatocytes incubated with T(4) at concentration of 1000 ng/mL exhibited a significant elevation in IGF-I expression, whereas no difference in IGF-I expression was demonstrated in hepatocytes after incubation with T(3). Upon incubation with cortisol (1-1000 ng/mL), IGF-I expression was significantly decreased in hepatocytes in a dose-dependent manner. Our study demonstrated that GH, T(4), and cortisol had direct modulatory effects on IGF-I expression in fish hepatocytes in vitro.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • DNA Primers / genetics
  • Gene Expression / drug effects
  • Glucosephosphate Dehydrogenase / genetics
  • Growth Hormone / pharmacology*
  • Hepatocytes / drug effects*
  • Hepatocytes / metabolism*
  • Humans
  • Hydrocortisone / pharmacology*
  • Insulin-Like Growth Factor I / genetics*
  • Insulin-Like Growth Factor I / pharmacology
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Recombinant Proteins / pharmacology
  • Sea Bream / genetics*
  • Sea Bream / growth & development
  • Sea Bream / metabolism
  • Thyroxine / pharmacology*
  • Triiodothyronine / pharmacology

Substances

  • DNA Primers
  • RNA, Messenger
  • Recombinant Proteins
  • Triiodothyronine
  • Insulin-Like Growth Factor I
  • Growth Hormone
  • Glucosephosphate Dehydrogenase
  • Thyroxine
  • Hydrocortisone