EFFECT OF PARAXANTHINE ON FFA MOBILIZATION AFTER INTRAVENOUS CAFFEINE ADMINISTRATION IN HUMANS
EFFECT OF PARAXANTHINE ON FFA MOBILIZATION AFTER INTRAVENOUS CAFFEINE ADMINISTRATION IN HUMANS
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DOI：
10.1152/jappl.1990.68.1.44
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发表时间：
1990-01-01
影响因子：
3.3
通讯作者：
PERKINS, RM
中科院分区：
文献类型：
--
作者：
HETZLER, RK;KNOWLTON, RG;PERKINS, RM
因为之前已经表明，在体外引起脂肪动员需要比体内多得多的咖啡因，因此有人认为可能存在与咖啡因一起作用的活性代谢物，导致体内脂肪分解增加。为了确定静脉注射咖啡因后副黄嘌呤（咖啡因的主要二甲基黄嘌呤代谢物）的出现与游离脂肪酸 (FFA) 动员之间的关系，对 10 名男性在接受 4 毫克/千克去脂体重剂量后休息时进行了研究。在给药前以及第 5、10、15、30、45、60、90、120、150 和 180 分钟时采集静脉血样。一式两份测定 FFA、甘油、咖啡因和副黄嘌呤的血清水平。根据血浆体积变化校正 FFA 和甘油的浓度。咖啡因的减少和 FFA 的增加之间存在高度负相关 (r = -0.90)，副黄嘌呤的出现和 FFA 之间存在高度正相关 (r = 0.93)。结论是，在人体摄入咖啡因后，副黄嘌呤可能在增加脂肪分解方面发挥作用。
Because it has previously been shown that it takes much more caffeine to cause fat mobilization in vitro than in vivo, it has been suggested that there may be an active metabolite working with caffeine causing an increase in lipolysis in vivo. To determine the relationship between appearance of paraxanthine (caffeine''s major dimethylxanthine metabolite) and free fatty acid (FFA) mobilization after intravenous caffeine administration, 10 men were studied at rest after receiving a dose of 4 mg/kg lean body mass. Venous blood samples were obtained before dosing and at minutes 5, 10, 15, 30, 45, 60, 90, 120, 150, and 180. Serum levels of FFA, glycerol, caffeine, and paraxanthine were determined in duplicate. Concentrations of FFA and glycerol were corrected for plasma volume changes. A high negative correlation was seen between decreases in caffeine and increases in FFA (r = -0.90) and a high positive correlation was seen between the appearance of paraxanthine and FFA (r = 0.93). It was concluded that paraxanthine may play a role in increased lipolysis after caffeine administration in humans.