Sumiyoshi Maho, Sakanaka Masahiro, Kimura Yoshiyuki
Division of Functional Histology, Department of Integrated Basic Medical Science, Ehime University, Shitsukawa, Toon City,, Japan.
J Nutr. 2006 Mar;136(3):582-7. doi: 10.1093/jn/136.3.582.
Intakes of some macronutrients can comprise risk factors for life-style-related diseases such as obesity, hyperlipidemia, diabetes, hypertension, and atherosclerosis. In this study, we examined the effects in C57BL/6J mice of consuming excess fat or sucrose for a long period of time (55 wk). Another group of mice consumed a low-fat, low-sucrose (LL) diet. Mice fed the high-fat (HF) diet gained weight and developed hyperlipidemia and hyperleptinemia. At 25 wk, but not at 55 wk, hepatic glucose-6-phosphatase (G6Pase) activity of the mice fed the high sucrose (HS) diet was greater than that of mice fed the LL or HF diet. Those fed the HS diet were not obese and had greater hepatic lipogenic and gluconeogenic enzyme activities. The HF and HS diets resulted in different types of glucose intolerance. In an oral glucose tolerance test, mice fed the HF diet had a delay in the clearance of glucose compared with those fed the LL diet, perhaps due to the peripheral insulin resistance that resulted from higher levels of circulating free fatty acids. Feeding the HS diet for 55 wk induced hyperglycemia 10 min after oral glucose administration, although blood glucose declined rapidly after i.p. insulin injection. This finding suggests that the effects of chronic HS diet intake may be due to the reduction in early insulin secretion from pancreatic islets and the increase in sucrase activity in the small intestine. It is important to consider the effects of macronutrients in lean as well as obese mice to clarify the pathogenesis of the metabolic disorders.
某些常量营养素的摄入量可能构成肥胖、高脂血症、糖尿病、高血压和动脉粥样硬化等生活方式相关疾病的风险因素。在本研究中，我们检测了长期（55周）摄入过量脂肪或蔗糖对C57BL/6J小鼠的影响。另一组小鼠食用低脂、低蔗糖（LL）饮食。喂食高脂（HF）饮食的小鼠体重增加，并出现高脂血症和高瘦素血症。在25周时，喂食高蔗糖（HS）饮食的小鼠肝葡萄糖-6-磷酸酶（G6Pase）活性高于喂食LL或HF饮食的小鼠，但在55周时则不然。喂食HS饮食的小鼠不肥胖，且具有更高的肝脂肪生成和糖异生酶活性。HF和HS饮食导致了不同类型的葡萄糖不耐受。在口服葡萄糖耐量试验中，与喂食LL饮食的小鼠相比，喂食HF饮食的小鼠葡萄糖清除延迟，这可能是由于循环游离脂肪酸水平升高导致的外周胰岛素抵抗。喂食HS饮食55周后，口服葡萄糖10分钟后出现高血糖，尽管腹腔注射胰岛素后血糖迅速下降。这一发现表明，长期摄入HS饮食的影响可能是由于胰岛早期胰岛素分泌减少和小肠蔗糖酶活性增加。考虑常量营养素对瘦小鼠和肥胖小鼠的影响对于阐明代谢紊乱的发病机制很重要。
