Sato Kazusa, Arai Hidekazu, Miyazawa Yui, Fukaya Makiko, Uebanso Takashi, Koganei Megumi, Sasaki Hajime, Sato Tadatoshi, Yamamoto Hironori, Taketani Yutaka, Takeda Eiji
Department of Clinical Nutrition, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan.
J Med Invest. 2008 Aug;55(3-4):183-95. doi: 10.2152/jmi.55.183.
We showed previously that 8-wk consumption of a diet containing palatinose (P, a slowly-absorbed sucrose analogue) and oleic acid (O) ameliorates but a diet containing sucrose (S) and linoleic acid (L) aggravates metabolic abnormalities in Zucker fatty (fa/fa) rats. In this study, we aimed to identify early changes in metabolism in rats induced by certain combinations of carbohydrates and fatty acids. Specifically, male Zucker fatty rats were fed an isocaloric diet containing various combinations of carbohydrates (P; S) and fatty acids (O; L). After 4 wk, no significant differences in body weight, visceral fat mass, plasma parameters (glucose, insulin, lipids, and adipokines), hepatic adiposity and gene expression, and adipose inflammation were observed between dietary groups. In contrast, pancreatic islets of palatinose-fed (PO and PL) rats were smaller and less fibrotic than sucrose-fed (SO and SL) rats. The abnormal alpha-cell distribution and sporadic staining of active caspase-3 common to islets of linoleic-acid-fed rats were not observed in oleic-acid-fed (PO and SO) rats. Accordingly, progressive beta-cell loss was seen in SL rats, but not in PO rats. These findings suggest that pancreatic islets may be initial sites that translate the effects of different combinations of dietary carbohydrates and fats into metabolic changes.
我们之前的研究表明，连续8周食用含有帕拉金糖（P，一种吸收缓慢的蔗糖类似物）和油酸（O）的饮食可改善代谢异常，而含有蔗糖（S）和亚油酸（L）的饮食则会加重Zucker肥胖（fa/fa）大鼠的代谢异常。在本研究中，我们旨在确定由某些碳水化合物和脂肪酸组合诱导的大鼠代谢早期变化。具体而言，给雄性Zucker肥胖大鼠喂食含有碳水化合物（P；S）和脂肪酸（O；L）各种组合的等热量饮食。4周后，各饮食组之间在体重、内脏脂肪量、血浆参数（葡萄糖、胰岛素、脂质和脂肪因子）、肝脏脂肪变性和基因表达以及脂肪炎症方面均未观察到显著差异。相比之下，喂食帕拉金糖（PO和PL）的大鼠胰岛比喂食蔗糖（SO和SL）的大鼠胰岛更小且纤维化程度更低。在喂食油酸（PO和SO）的大鼠中未观察到喂食亚油酸的大鼠胰岛常见的异常α细胞分布和活性半胱天冬酶-3的散在染色。因此，在SL大鼠中观察到β细胞逐渐丢失，但在PO大鼠中未观察到。这些发现表明，胰岛可能是将饮食中碳水化合物和脂肪的不同组合的影响转化为代谢变化的初始部位。
