Insulin-like growth factor-I stimulates acromegaly-like specific mandibular enlargement in rats

M. Iikubo, H. Ikeda, A. Kobayashi, I. Kojima, K. Hashimoto, Maya Sakamoto, Takashi Sasano

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


To help us investigate the time course of mandibular enlargement in acromegaly or acrogiantism to determine the most suitable period for occlusal treatment in this disease, our aim was to develop a rat model of acromegaly (acrogiantism). In this study, prominent mandibular enlargement was induced by continuous subcutaneous infusion of human recombinant insulin-like growth factor-I (IGF-I) (640 μg/day) in 10-week-old male rats for 4 weeks (n = 6); the control sham-operated group was injected with saline alone (n = 6). Circulating human IGF-I was clearly detectable in the IGF-I group during the four-week administration period, while endogenous rat IGF-I levels decreased. Total IGF-I (human + rat) increased significantly during administration, returning to control levels afterwards. The length of every bone examined (mandible, maxilla, and femur) showed a significant increase compared to control rats, especially the mandible. Although the mandible did not continue to grow after discontinuation of IGF-I administration, it did not return to control size, unlike the maxilla and femur, and disharmonious jaw size (between maxilla and mandible) persisted even after circulating IGF-I levels normalized. These findings in our rat model suggest that mandibular occlusal treatment should only be considered for acromegalic (acrogiantic) patients after serum IGF-I levels have normalized and bone growth has ceased.

Original languageEnglish
Pages (from-to)696-701
Number of pages6
JournalHormone and Metabolic Research
Issue number10
Publication statusPublished - 2004 Oct


  • Acromegaly
  • Bone growth
  • IGF-I
  • Mandibular enlargement
  • Rat Model

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Endocrinology
  • Clinical Biochemistry
  • Biochemistry, medical


Dive into the research topics of 'Insulin-like growth factor-I stimulates acromegaly-like specific mandibular enlargement in rats'. Together they form a unique fingerprint.

Cite this