Anti-atherogenic effect of insulin in vivo
| Autor: | Jiwanjeet K. Dhaliwall, Michelle P. Bendeck, Kalam K. Chan, Hiroshi Uchino, Renee Suen, Tony Kim, Nghia Huynh, Adria Giacca, Dinaz Naigamwalla |
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| Rok vydání: | 2004 |
| Předmět: |
Male
medicine.medical_specialty Physiology medicine.medical_treatment Hyperlipidemias Biology Catheterization Rats Sprague-Dawley Insulin resistance In vivo Internal medicine Hyperinsulinism Hyperlipidemia medicine Hyperinsulinemia Animals Insulin Pancreatic hormone Drug Implants Dose-Response Relationship Drug medicine.disease Atherosclerosis Dietary Fats Rats Endocrinology Carotid Arteries Metabolic syndrome Cardiology and Cardiovascular Medicine Carotid Artery Injuries Tunica Intima Cell Division |
| Zdroj: | Journal of vascular research. 42(6) |
| ISSN: | 1018-1172 |
| Popis: | Metabolic syndrome is a risk factor for atherosclerosis and restenosis. In metabolic syndrome, insulin resistance coexists with hyperinsulinemia and hyperlipidemia. Hyperlipidemia has growth-promoting effects, whereas insulin has both growth-promoting and growth-inhibitory effects on vascular smooth muscle cells in vitro. The objective of this study was to investigate the effects of hyperlipidemia and hyperinsulinemia on vascular cell growth in vivo after arterial injury. Rats fed a low-fat diet were treated with either subcutaneous blank (LFC) or insulin (LFI) implants. Rats fed a high-fat diet also received blank (HFC) or insulin (HFI) implants. After 3 days, rats received balloon carotid injury, and 14 days later they were sacrificed to measure neointimal area and proliferation. Hyperinsulinemia was present in LFI and HFI and hyperlipidemia was present in HFC and HFI. Neointimal area was higher in HFC (0.153 ± 0.009 mm2, p < 0.05) but lower in LFI (0.098 ± 0.005, p < 0.01) than LFC (0.127 ± 0.005). In HFI (0.142 ± 0.008, p < 0.05) neointimal area was not different from HFC or LFC. In conclusion, insulin reduced neointimal growth, but the effect of insulin was diminished by the high-fat diet. Thus, our results demonstrate an anti-atherogenic effect of insulin in vivo and suggest that in metabolic syndrome insulin resistance rather than hyperinsulinemia is the atherogenic risk factor. |
| Databáze: | OpenAIRE |
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