Sultan Ahmed, Adeghate Ernest, Emerald Bright Starling, Qureshi Muhammad A, Minhas Saeed Tariq, Howarth Frank Christopher
Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain P.O. Box 17666, United Arab Emirates.
Department of Anatomy, College of Medicine & Health Sciences, UAE University, Al Ain P.O. Box 17666, United Arab Emirates.
Life (Basel). 2022 Aug 11;12(8):1221. doi: 10.3390/life12081221.
(1) Background: Cardiovascular complications are a leading cause of morbidity and mortality in diabetic patients. The effects of obesity and diabesity on the function and structure of ventricular myocytes in the Zucker fatty (ZF) rat and the Zucker diabetic fatty (ZDF) rat compared to Zucker lean (ZL) control rats have been investigated. (2) Methods: Shortening and intracellular Ca were simultaneously measured with cell imaging and fluorescence photometry, respectively. Ventricular muscle protein expression and structure were investigated with Western blot and electron microscopy, respectively. (3) Results: The amplitude of shortening was increased in ZF compared to ZL but not compared to ZDF myocytes. Resting Ca was increased in ZDF compared to ZL myocytes. Time to half decay of the Ca transient was prolonged in ZDF compared to ZL and was reduced in ZF compared to ZL myocytes. Changes in expression of proteins associated with cardiac muscle contraction are presented. Structurally, there were reductions in sarcomere length in ZDF and ZF compared to ZL and reductions in mitochondria count in ZF compared to ZDF and ZL myocytes. (4) Conclusions: Alterations in ventricular muscle proteins and structure may partly underlie the defects observed in Ca signaling in ZDF and ZF compared to ZL rat hearts.
(1) 背景：心血管并发症是糖尿病患者发病和死亡的主要原因。与正常的Zucker瘦鼠（ZL）相比，已对肥胖型Zucker鼠（ZF）和糖尿病肥胖型Zucker鼠（ZDF）心室肌细胞的功能和结构受肥胖及糖尿病的影响进行了研究。(2) 方法：分别通过细胞成像和荧光光度法同时测量肌节缩短和细胞内钙浓度。分别用蛋白质印迹法和电子显微镜研究心室肌蛋白表达和结构。(3) 结果：与ZL相比，ZF肌细胞的缩短幅度增加，但与ZDF肌细胞相比无差异。与ZL肌细胞相比，ZDF肌细胞的静息钙浓度升高。与ZL相比，ZDF肌细胞的钙瞬变半衰期延长，而与ZL相比，ZF肌细胞的钙瞬变半衰期缩短。展示了与心肌收缩相关蛋白表达的变化。在结构上，与ZL相比，ZDF和ZF的肌节长度缩短，与ZDF和ZL相比，ZF肌细胞的线粒体数量减少。(4) 结论：与ZL大鼠心脏相比，ZDF和ZF大鼠心脏中观察到的钙信号缺陷可能部分归因于心室肌蛋白和结构的改变。
