Central opiate modulation of growth hormone and insulin-like growth factor-I

Yojiro Hashiguchi, Patricia E. Molina, Jie Fan, Charles H. Lang, Naji N. Abumrad

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


The effects of central administration of morphine-sulfate (MOR:80 μg) and morphine-6-glucuronide (M6G:1 μg) on the growth hormone (GH)/insulin-like growth factor (IGF) system were assessed. MOR and M6G were injected intracerebroventricularly (ICV) in chronically catheterized 24 h fasted rats; time-matched control animals received H2O (5 μl). MOR increased plasma GH concentrations 3-fold 2 h after ICV injection, and transiently increased the plasma concentration and liver content of IGF-I (60% and 90%, respectively) 30 min after ICV injection. M6G did not produce any significant alterations in plasma GH and IGF-I levels at the time-points measured. Both MOR and M6G increased the concentration of IGF binding protein-1 (IGFBP-1) in plasma and liver 2 h after injection. However, MOR showed 2- to 2.5-fold greater effect than M6G in stimulating plasma and liver IGFBP-1. MOR and M6G produced similar increases in plasma epinephrine (5-fold), norepinephrine (3-fold) and corticosterone (1.5-fold). Neither opiate significantly altered circulating insulin levels. These findings suggest that opiate modulation of GH and IGF may be hormone-independent and centrally modulated. We speculate that differential affinities of MOR and M6G to the different opiate receptor subtypes might be responsible for their distinct effects on GH/IGF-I system.

Original languageEnglish (US)
Pages (from-to)99-104
Number of pages6
JournalBrain Research Bulletin
Issue number2
StatePublished - 1996

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)


Dive into the research topics of 'Central opiate modulation of growth hormone and insulin-like growth factor-I'. Together they form a unique fingerprint.

Cite this