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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
5
|
| pubmed:dateCreated |
1989-6-6
|
| pubmed:abstractText |
A new mutant GH-deficient dwarf rat has been used to study the effects of iv infusions of human GH (hGH) and recombinant human insulin-like growth factor I (hIGF-I). This animal has only about 5% of normal pituitary GH content, low circulating GH levels, and no regular GH surges. The defect seems to be specific for GH. Infusions of hIGF-I at 180 micrograms/day for 9 days elevated serum IGF-I concentrations significantly over those in the saline-infused controls (713 +/- 20 ng/ml vs. 395 +/- 31 ng/ml); hGH infusions did not raise IGF-I levels significantly (435 +/- 20 ng/ml). Gel filtration of serum samples showed that the high-dose hIGF-I infusions increased free IGF concentrations, without apparently altering the pattern of IGF-I binding whereas hGH infusions increased the amount of high mol wt IGF-I binding protein. Neither IGF-I nor hGH infusions affected the small amounts of rat GH present in the dwarf rat pituitary glands. Continuous iv infusions of hGH (200 mU/day for 9 days) stimulated body wt gain (2.1 +/- 0.2 g/day) and bone growth (96 +/- 9 microns/day) significantly compared to saline-infused dwarf rats (1.2 +/- 0.3 g/day and 43 +/- 3 microns/day). Infusions of hIGF-I at 180 micrograms/day produced a body wt gain (2.1 +/- 0.5 g/day) similar to that seen in the hGH-infused group but a significantly smaller stimulation of bone growth (63 +/- 3 microns/day). Infusion of a 5-fold lower dose of hIGF-I (36 micrograms/day for 9 days) had no effect on body wt or bone growth. Food intake was unaffected by either hGH or hIGF-I infusions. The pattern of tissue growth was affected differentially by hGH and IGF-I infusions that produced the same overall body wt gain. hGH induced a relatively proportional growth in most of the organs studied, whereas hIGF-I infusion at 180 micrograms/day stimulated a disproportionately greater growth of the kidney, adrenals, and spleen. In some of the animals, tissues were extracted for RIA of IGF-I; the amounts of IGF-I in the liver were similar in control, hGH, or IGF-I-infused animals, whereas kidney and adrenals from IGF-I infused animals contained larger amounts of immunoreactive IGF-I than did those tissues from hGH-treated rats. Thus, both hGH and hIGF-I can promote growth in the mutant dwarf rat, but they differ both quantitatively and qualitatively in their pattern of actions.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
AIM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
May
|
| pubmed:issn |
0013-7227
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
124
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
2519-26
|
| pubmed:dateRevised |
2004-11-17
|
| pubmed:meshHeading |
pubmed-meshheading:2707163-Animals,
pubmed-meshheading:2707163-Body Weight,
pubmed-meshheading:2707163-Bone Development,
pubmed-meshheading:2707163-Dwarfism,
pubmed-meshheading:2707163-Growth Hormone,
pubmed-meshheading:2707163-Humans,
pubmed-meshheading:2707163-Insulin-Like Growth Factor I,
pubmed-meshheading:2707163-Organ Size,
pubmed-meshheading:2707163-Rats,
pubmed-meshheading:2707163-Rats, Mutant Strains,
pubmed-meshheading:2707163-Recombinant Proteins,
pubmed-meshheading:2707163-Somatomedins
|
| pubmed:year |
1989
|
| pubmed:articleTitle |
Growth responses in a mutant dwarf rat to human growth hormone and recombinant human insulin-like growth factor I.
|
| pubmed:affiliation |
Kabi Peptide Hormones, Research and Development, Stockholm, Sweden.
|
| pubmed:publicationType |
Journal Article
|