These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Differential long-term effects of insulin-like growth factor-I (IGF-I) growth hormone (GH), and IGF-I plus GH on body growth and IGF binding proteins in hypophysectomized rats.
    Author: Fielder PJ, Mortensen DL, Mallet P, Carlsson B, Baxter RC, Clark RG.
    Journal: Endocrinology; 1996 May; 137(5):1913-20. PubMed ID: 8612531.
    Abstract:
    The long-term effects of recombinant human insulin-like growth factor-I (rhIGF-I) and GH (rhGH) on body growth and the IGF-I/IGF binding protein (IGFBP)/acid-labile subunit (ALS) axis were investigated in hypophysectomized (hypox) rats given excipient, rhIGF-I (2 mg/kg.day s.c., minipumps), rhGH (2 mg/kg.day, s.c., daily injections), or rhIGF-I plus rhGH for 28 days. The relative growth-promoting activity of the treatments was rhGH plus rhIGF-I more than rhGH more than rhIGF-I. Weight gain induced by rhIGF-I progressively declined after 4 days, compared with a more maintained effect of rhGH. At day 28, growth responses did not correlate with serum IGF-I levels [rhGH plus rhIGF-I (492 +/- 140) > rhIGF-I (322 +/- 75) > rhGH (85 +/- 26) > control (39 +/- 7 ng/ml)]. Serum ALS concentrations in hypox rats were remarkably low (0.42 +/- 0.04 micrograms/ml) but were restored toward normal by rhGH (12.55 +/- 4.78) or rhGH plus rhIGF-I (12.85 +/- 6.64) but not by rhIGF-I alone (0.85 +/- 0.25). Antibodies against rhGH were present at day 28, with titer being negatively related to weight gain, IGF-I, and ALS levels. All treatments increased serum IGFBP-3. The molecular size distribution of IGFBP-3 in rhGH-treated rats was similar to that of normal rats (IGFBP-3 in the 150K mol wt range), due to rhGH increasing serum ALS, but was altered by rhIGF-I (IGFBP-3 in the 200-300K and 44K mol wt range). In a GH-deficient animal, restoring the IGF/IGFBP-3/ALS axis towards normal is associated with greater growth promotion.
    [Abstract] [Full Text] [Related] [New Search]