Non-insulin- and insulin-mediated glucose uptake in dairy cows
Non-insulin- and insulin-mediated glucose uptake in dairy cows
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DOI：
10.1017/s0022029997002215
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发表时间：
1997-08-01
影响因子：
2.1
通讯作者：
Takahashi, Y
中科院分区：
文献类型：
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作者：
Rose, MT;Obara, Y;Takahashi, Y
四头泌乳中期荷斯坦奶牛（实验当天的平均产奶量为 26.1 kg/d）被用于一系列实验，以确定基础胰岛素浓度下非胰岛素介导的葡萄糖摄取对总葡萄糖摄取的贡献。第二个目标是确定生长抑素是否影响输注胰岛素的作用。在实验的第一部分中，在时间0开始连续输注[6,6-H-2]葡萄糖（45.2μg/kg/分钟）并持续5小时。 [6,6-H-2]葡萄糖输注3小时（基础期）后，开始连续输注胰岛素（0.001 i.u./kg/min）2小时。在输注胰岛素的同时，还输注正常葡萄糖，以将血浆葡萄糖浓度维持在正常血糖。实验第二部分与第一部分相同，只是输注生长抑素2小时（0.333μg/kg/min）而不是胰岛素。在实验的第三部分中，最后 2 小时注射了胰岛素和生长抑素。相对于基础期（平均 0.021 i.u./l），胰岛素输注可增加血浆胰岛素水平（第一部分和第三部分分别为 0.1476 和 0.1290 i.u./l），而第二部分则通过生长抑素输注而降低（至 0.006 i.u./l）。生长抑素输注期间的葡萄糖摄取（2.50mg/kg/分钟；第二部分）是相应基础期观察到的葡萄糖摄取（2.72mg/kg/分钟）的92.0%。循环胰岛素水平远低于对葡萄糖摄取产生最大影响一半的胰岛素剂量（反刍动物为 0.06-0.10 i.u./l）；因此，第二部分可能不存在胰岛素介导的葡萄糖摄取。其次，仅输注胰岛素后的葡萄糖摄取（4.05 mg/kg/min）显着低于输注胰岛素加生长抑素（4.69 mg/kg/min）时观察到的葡萄糖摄取，表明生长抑素直接或间接增强了胰岛素对葡萄糖摄取的作用。
Four mid-lactation Holstein dairy cows (mean milk yield on day of experiments 26.1 kg/d) were used in a series of experiments to establish the contribution of non-insulin-mediated glucose uptake to total glucose uptake at basal insulin concentrations. A secondary objective was to determine whether somatostatin affects the action of infused insulin. In part I of the experiment a primed continuous infusion of [6,6-H-2]glucose (45.2 mu g/kg per min) was begun at time 0 and continued for 5 h. After 3 h of [6,6-H-2]glucose infusion (basal period) a primed continuous infusion of insulin (0.001 i.u./kg per min) was administered for 2 h. Coincident with the insulin infusion, normal glucose was also infused in order to maintain the plasma glucose concentration at euglycaemia. Part II of the experiment was the same as part I except that somatostatin was infused for 2 h (0.333 mu g/kg per min) instead of insulin. In part III of the experiment both insulin and somatostatin were infused for the final 2 h. Plasma insulin levels were increased by insulin infusion (to 0.1476 and 0.1290 i.u./l for parts I and III respectively) and were reduced by somatostatin infusion in part II (to 0.006 i.u./l) relative to the basal periods (mean 0.021 i.u./l). Glucose uptake during somatostatin infusion (2.50 mg/kg per min; part II) was 92.0 % of that observed in the respective basal period (2.72 mg/kg per min). Circulating insulin levels were much lower than the dose of insulin that causes a half maximal effect on glucose uptake (0.06-0.10 i.u./l for ruminants); consequently insulin-mediated glucose uptake was probably absent in part II. Secondly, glucose uptake following insulin only infusion (4.05 mg/kg per min) was significantly lower than that observed when insulin plus somatostatin was infused (4.69 mg/kg per min), indicating that somatostatin either directly or indirectly enhanced the action of insulin on glucose uptake.