Insulin Like Growth Factor-1 (IGF-1) Causes Overproduction of IL-8, an Angiogenic Cytokine and Stimulates Neovascularization in Isoproterenol-Induced Myocardial Infarction in Rats

International Journal of Molecular Sciences

Nagaraja Haleagrahara¹  Srikumar Chakravarthi² 

[1] Faculty of Medicine, Health and Molecular Sciences, James Cook University, Townsville 4811, Queensland, Australia;Division of Pathology, International Medical University, Kuala Lumpur 57000, Malaysia; E-Mail:

关键词: IGF-1;    isoproterenol;    myocardial ischemia;    angiogenesis;    interleukin-8;   

DOI  :  10.3390/ijms12128562

来源: mdpi

【 摘 要 】

Angiogenesis factors are produced in response to hypoxic or ischemic insult at the site of pathology, which will cause neovascularization. Insulin like growth factor-1 (IGF-1) exerts potent proliferative, angiogenic and anti-apoptotic effects in target tissues. The present study was aimed to evaluate the effects of IGF-1 on circulating level of angiogenic cytokine interleukin-8 (IL-8), in experimentally-induced myocardial ischemia in rats. Male Sprague-Dawley rats were divided into control, IGF-1 treated (2 μg/kg/day subcutaneously, for 5 and 10 days), isoproterenol (ISO) treated (85 mg/kg, subcutaneously for two days) and ISO with IGF-1 treated (for 5 and 10 days). Heart weight, serum IGF-1, IL-8 and cardiac marker enzymes (CK-MB and LDH) were recorded after 5 and 10 days of treatment. Histopathological analyses of the myocardium were also done. There was a significant increase in serum cardiac markers with ISO treatment indicating myocardial infarction in rats. IGF-1 level increased significantly in ISO treated groups and the level of IGF-1 was significantly higher after 10 days of treatment. IL-8 level increased significantly after ISO treatment after 5 and 10 days and IGF-1 concurrent treatment to ISO rats had significantly increased IL-8 levels. Histopathologically, myocyte necrosis and nuclear pyknosis were reduced significantly in IGF-1 treated group and there were numerous areas of capillary sprouting suggestive of neovascularization in the myocardium. Thus, IGF-1 protects the ischemic myocardium with increased production of circulating angiogenic cytokine, IL-8 and increased angiogenesis.

【 授权许可】

CC BY   
© 2011 by the authors; licensee MDPI, Basel, Switzerland.