| 摘要: | Background. Obesity is often associated with the development of dilated cardiac hypertrophy but the precise mechanisms remain uncertain. The purpose of this study was to evaluate cardiac hypertrophy, tumor necrosis factor-alpha (TNFα) and the key components of interleukin (IL)-6-MEK5-ERK5 hypertrophic pathway in the excised heart from obesity. Methods. Twelve obese Zucker rats were studied at 5-6 months of age and twelve age-matched lean Zucker rats served as control. The cardiac characteristics, myocardial architecture, TNFα levels, IL-6, MEK5, and ERK-5 in the excised left ventricle from rats were measured by heart weight index, vertical cross section, histological analysis, reverse transcription polymerase chain reaction (RT-PCR), and Western blotting. Results. The whole heart weight, the left ventricular weight, the ratio of whole heart weight to tibia length, the vertical cross section of gross heart, and myocardial morphological changes were increased in obese rats. The gene expression and protein products of TNFα were significantly increased as well as the protein products of IL-6, MEK-5, and ERK-5 were significantly increased in obese rat heart. Conclusions. The eccentric hypertrophy related pathways, TNFα levels and IL-6 related MEK5-ERK5 pathway were more active in obese Zucker rat, which may provide possible hypertrophic mechanisms for developing eccentric cardiac hypertrophy and pathological changes in obesity. |
