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Insulin and IGF-I a...
Insulin and IGF-I action on insulin receptors, IGF-I receptors, and hybrid insulin/IGF-I receptors in vascular smooth muscle cells
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- Johansson, Git S, 1979- (författare)
- Linköpings universitet,Cellbiologi,Hälsouniversitetet,Hans Arnqvist
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- Arnqvist, Hans J (författare)
- Östergötlands Läns Landsting,Linköpings universitet,Cellbiologi,Hälsouniversitetet,Endokrin- och magtarmmedicinska kliniken US
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(creator_code:org_t)
- Rockville Pike : American Physiological Society, 2006
- 2006
- Engelska.
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Ingår i: American Journal of Physiology. Endocrinology and Metabolism. - Rockville Pike : American Physiological Society. - 0193-1849 .- 1522-1555. ; 291:5, s. 1124-1130
- Relaterad länk:
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http://urn.kb.se/res...
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- Insulin and insulin-like growth factor I (IGF-I) are known to affect cardiovascular disease. We have investigated ligand binding and the dose-response relationship for insulin and IGF-I on vascular smooth muscle cells (VSMCs) at the receptor level. VSMCs from rat thoracic aorta were serum starved, stimulated with IGF-I or insulin, lysed, immunoprecipitated, and analyzed by Western blot. D-[U-14C]Glucose accumulation and [6-3H]thymidine incorporation into DNA were also measured. Specific binding of both insulin and IGF-I was demonstrated, being higher for IGF-I. Both IGF-I receptor (IGF-IR) and insulin receptor (IR) β-subunits were detected and coprecipitated after immunoprecipitation (IP) against either of the two. No coprecipitation was found after reduction of disulphide bonds with dithiotreitol before IP. After stimulation with 10–10–10–9 M IGF-I, IP of the IGF-IR, or IR β-subunit and immunoblot with anti-phosphotyrosine antibody, we found two distinct bands indicating phosphorylation of both the IGF-IR and the IR β-subunit. Stimulation with 10–10–10–9 M insulin and IP against the IGF-IR did not show phosphorylation of either β-subunit, whereas after IP of the IR we found phosphorylation of the IR β-subunit. [14C]Glucose accumulation and [3H]thymidine incorporation were elevated in cells stimulated with IGF-I at 10–10–10–7 M, reaching maximum by 10–9 M. Insulin stimulation showed measurable effects only at supraphysiological concentrations, 10–8–10–7 M. In conclusion, coprecipitation of both the IGF-IR and the IR β-subunit indicates the presence of hybrid insulin/IGF-I receptors in VSMC. At a physiological concentration, insulin activates the IR but does not affect either glucose metabolism or DNA synthesis, whereas IGF-I both activates the receptor and elicits biological effect.
Ämnesord
- MEDICIN OCH HÄLSOVETENSKAP -- Medicinska och farmaceutiska grundvetenskaper -- Cell- och molekylärbiologi (hsv//swe)
- MEDICAL AND HEALTH SCIENCES -- Basic Medicine -- Cell and Molecular Biology (hsv//eng)
Nyckelord
- insulin-like growth factor I
- ligand binding
- receptor phosphorylation
- immunoprecipitation
- deoxyribonucleic acid synthesis
- glucose metabolism
- Medical cell biology
- Medicinsk cellbiologi
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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