Pinotti M F, Silva M D P, Sugizaki M M, Diniz Y S, Sant'Ana L S, Aragon F F, Padovani C R, Novelli E L B, Cicogna A C
Departamento de Clínica Médica, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista Júlio de Mesquita Filho, Botucatu, SP, Brazil.
Braz J Med Biol Res. 2006 Feb;39(2):305-12. doi: 10.1590/s0100-879x2006000200019. Epub 2006 Feb 2.
Diets rich in saturated fatty acids are one of the most important causes of atherosclerosis in men, and have been replaced with diets rich in unsaturated fatty acids (UFA) for the prevention of this disorder. However, the effect of UFA on myocardial performance, metabolism and morphology has not been completely characterized. The objective of the present investigation was to evaluate the effects of a UFA-rich diet on cardiac muscle function, oxidative stress, and morphology. Sixty-day-old male Wistar rats were fed a control (N = 8) or a UFA-rich diet (N = 8) for 60 days. Myocardial performance was studied in isolated papillary muscle by isometric and isotonic contractions under basal conditions after calcium chloride (5.2 mM) and ss-adrenergic stimulation with 1.0 microM isoproterenol. Fragments of the left ventricle free wall were used to study oxidative stress and were analyzed by light microscopy, and the myocardial ultrastructure was examined in left ventricle papillary muscle. After 60 days the UFA-rich diet did not change myocardial function. However, it caused high lipid hydroperoxide (176 +/- 5 vs 158 +/- 5, P < 0.0005) and low catalase (7 +/- 1 vs 9 +/- 1, P < 0.005) and superoxide-dismutase (18 +/- 2 vs 27 +/- 5, P < 0.005) levels, and discrete morphological changes in UFA-rich diet hearts such as lipid deposits and mitochondrial membrane alterations compared to control rats. These data show that a UFA-rich diet caused myocardial oxidative stress and mild structural alterations, but did not change mechanical function.
富含饱和脂肪酸的饮食是男性动脉粥样硬化最重要的病因之一，目前已被富含不饱和脂肪酸（UFA）的饮食所取代，用于预防这种疾病。然而，UFA对心肌性能、代谢和形态的影响尚未完全明确。本研究的目的是评估富含UFA的饮食对心肌功能、氧化应激和形态的影响。将60日龄雄性Wistar大鼠分为对照组（N = 8）或富含UFA饮食组（N = 8），喂养60天。在基础条件下，通过等长和等张收缩，在氯化钙（5.2 mM）和1.0 microM异丙肾上腺素的β-肾上腺素能刺激后，对分离的乳头肌进行心肌性能研究。取左心室游离壁碎片用于研究氧化应激，并通过光学显微镜进行分析，同时对左心室乳头肌的心肌超微结构进行检查。60天后，富含UFA的饮食并未改变心肌功能。然而，它导致脂质氢过氧化物水平升高（176±5 vs 158±5，P < 0.0005），过氧化氢酶（7±1 vs 9±1，P < 0.005）和超氧化物歧化酶水平降低（18±2 vs 27±5，P < 0.005），并且与对照大鼠相比，富含UFA饮食的心脏出现了离散的形态学变化，如脂质沉积和线粒体膜改变。这些数据表明，富含UFA的饮食会导致心肌氧化应激和轻度结构改变，但不会改变机械功能。
