Effects of chronic coffee consumption on glucose kinetics in the conscious rat
Effects of chronic coffee consumption on glucose kinetics in the conscious rat
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DOI：
10.1139/y07-070
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发表时间：
2007-08-01
影响因子：
2.1
通讯作者：
Wasserman, D. H.
中科院分区：
文献类型：
--
作者：
Shearer, J.;Sellars, E. A.;Wasserman, D. H.
流行病学研究表明，经常喝咖啡可以降低患2型糖尿病的风险。尽管有这些发现，但咖啡消费产生这些影响的生物机制尚不清楚。本研究的目的是双重的：开发一种大鼠模型，将进一步描绘定期饮用咖啡对葡萄糖动力学的影响，并确定是否咖啡，有或没有咖啡因，改变胰岛素对体内葡萄糖动力学的作用。将雄性Sprague-Dawley大鼠喂食高脂肪饮食4周，并结合以下之一：（i）饮用水作为安慰剂（PL），（ii）脱咖啡因咖啡（2 g/100 mL）（DC），或（iii）将生物碱咖啡因（20 mg/100 mL）加入脱咖啡因咖啡（2 g/100 mL）（CAF）。将导管长期植入颈动脉和颈静脉中，分别用于采样和输注。复苏动物（术后5天）在高胰岛素-正常血糖钳夹（2 mU·kg（-1中心点）min（-1））前禁食5 h。将葡萄糖钳制在6 mmol/L，并给予同位素（2-脱氧-[C-14]葡萄糖和[3-（3）H]葡萄糖），以获得全身和组织特异性葡萄糖动力学指数。葡萄糖输注率和全身代谢清除率的措施在DC中大于PL或CAF，表明全身胰岛素敏感性增加。由于DC和CAF之间的唯一区别是生物碱咖啡因的添加，因此可以得出结论，咖啡因拮抗DC的有益作用。鉴于这些发现，脱咖啡因咖啡可能是一种对抗胰岛素抵抗的营养手段。
Epidemiological studies indicate that regular coffee consumption reduces the risk of developing type 2 diabetes. Despite these findings, the biological mechanisms by which coffee consumption exerts these effects are unknown. The aim of this study was twofold: to develop a rat model that would further delineate the effects of regular coffee consumption on glucose kinetics, and to determine whether coffee, with or without caffeine, alters the actions of insulin on glucose kinetics in vivo. Male Sprague-Dawley rats were fed a high-fat diet for 4 weeks in combination with one of the following: (i) drinking water as placebo (PL), (ii) decaffeinated coffee (2 g/100 mL) (DC), or (iii) alkaloid caffeine (20 mg/100 mL) added to decaffeinated coffee (2 g/100 mL) (CAF). Catheters were chronically implanted in a carotid artery and jugular vein for sampling and infusions, respectively. Recovered animals (5 days postoperative) were fasted for 5 h before hyperinsulinernic-euglycemic clamps (2 rnU-kg(-1 center dot)min(-1)). Glucose was clamped at 6 mmol/L and isotopes (2-deoxy- [C-14]glucose and [3-(3) H]glucose) were administered to obtain indices of whole-body and tissue-specific glucose kinetics. Glucose infusion rates and measures of whole-body metabolic clearance were greater in DC than in PL or CAF, indicating increased whole-body insulin sensitivity. As the only difference between DC and CAF was the addition of alkaloid caffeine, it can be concluded that caffeine antagonizes the beneficial effects of DC. Given these findings, decaffeinated coffee may represent a nutritional means of combating insulin resistance.