Zawalich W S, Dye E S, Matschinsky F M
Biochem J. 1979 Apr 15;180(1):145-52. doi: 10.1042/bj1800145.
The ability of glucosamine and N-acetylglucosamine to stimulate insulin secretion from perifused rat islets and the suitability of these hexoses to be metabolized in a static incubation was studied under various conditions. N-Acetylglucosamine alone stimulated insulin release with a threshold of 10 mM, with half-maximal effect at approx. 16 mM, and maximally at 20 mM. With higher concentrations stimulation was slightly diminished. Release caused by 20 mM-N-acetylglucosamine was unaffected by 30 mM-mannoheptulose, but was blocked by 2-deoxyglucose or iodoacetate (1 mM). At moderate concentrations, (2.75--20 mM), the metabolism of N-acetyl[1-3H]glucosamine was similar to that of [1-3H]glucose and secretion rates paralleled the corresponding rates of metabolism with these hexoses. Glucosamine (27.5 mM) alone weakly stimulated insulin secretion, which was unaltered by 30 mM-mannoheptulose but blocked by 2-deoxyglucose or iodoacetate. A lower rate of [1-3H]glucosamine metabolism appeared to account for its weaker stimulatory efficacy. Insulin release caused by 27.5 mM-glucosamine or 27.5 mM-N-acetylglucosamine in the presence of basal (2.75 mM) glucose was accurately predicted based on the summed metabolic rates of these compounds. The data strengthen the theory proposing that metabolites or cofactors generated during metabolism are essential for triggering insulin secretion.
在各种条件下，研究了氨基葡萄糖和N-乙酰氨基葡萄糖刺激经外周灌流的大鼠胰岛分泌胰岛素的能力，以及这些己糖在静态孵育中进行代谢的适宜性。单独的N-乙酰氨基葡萄糖刺激胰岛素释放的阈值为10 mM，在约16 mM时达到半数最大效应，在20 mM时达到最大效应。浓度更高时，刺激作用略有减弱。20 mM - N-乙酰氨基葡萄糖引起的释放不受30 mM - 甘露庚酮糖的影响，但被2-脱氧葡萄糖或碘乙酸盐（1 mM）阻断。在中等浓度（2.75 - 20 mM）下，N-乙酰[1-³H]氨基葡萄糖的代谢与[1-³H]葡萄糖的代谢相似，分泌速率与这些己糖相应的代谢速率平行。单独的氨基葡萄糖（27.5 mM）对胰岛素分泌的刺激作用较弱，30 mM - 甘露庚酮糖对其无影响，但被2-脱氧葡萄糖或碘乙酸盐阻断。较低的[1-³H]氨基葡萄糖代谢速率似乎是其刺激效果较弱的原因。基于这些化合物的总代谢速率，可以准确预测在基础葡萄糖（2.75 mM）存在下，27.5 mM - 氨基葡萄糖或27.5 mM - N-乙酰氨基葡萄糖引起的胰岛素释放。这些数据强化了一种理论，即代谢过程中产生的代谢产物或辅因子对于触发胰岛素分泌至关重要。
