Biggee B A, Blinn C M, McAlindon T E, Nuite M, Silbert J E
Edith Nourse Rogers Memorial Veterans Hospital, 200 Springs Road, Bedford, MA 01730, USA.
Ann Rheum Dis. 2006 Feb;65(2):222-6. doi: 10.1136/ard.2005.036368. Epub 2005 Aug 3.
Oral glucosamine preparations are widely used as a treatment for osteoarthritis, purportedly functioning by a variety of mechanisms suggested by results of in vitro experiments, and generally using glucosamine concentrations well in excess of 100 micromol/l.
To use high performance liquid chromatography with a high sensitivity Metrohm-Peak instrument for pulsed amperometric measurement of human serum glucosamine; a detection limit of 0.5 micromol/l at 1:10 serum dilution allowed measurement of low levels of glucosamine in human serum, which previously has not been possible.
Eighteen subjects with osteoarthritis were given 1,500 mg of commercial glucosamine sulphate after an overnight fast, and serum was then obtained at baseline and every 15-30 minutes over 3 hours, and additionally, from two subjects at 5 and 8 hours. Urine samples were collected at baseline and 3 hours after ingestion from three subjects.
Baseline glucosamine was below the detection limit of 0.5 mumol/l for all subjects, but after ingestion, glucosamine was detected in 17/18 subjects, beginning to rise at 30-45 minutes to a maximum at 90-180 minutes, with a range of 1.9-11.5 micromol/l (0.34-2 microg/ml).
This maximum concentration of 11.5 micromol/l has previously been shown to contribute less than 2% of the galactosamine incorporated into chondroitin sulphate in incubations of glucosamine with cultured human chondrocytes, and is a much lower concentration than the glucosamine concentrations claimed by other investigators to have various significant in vitro effects. This raises questions about current biological rationales for glucosamine use that were based on in vitro effects of glucosamine at much higher concentrations.
口服氨基葡萄糖制剂被广泛用于骨关节炎的治疗，据称其通过体外实验结果所提示的多种机制发挥作用，且通常使用远超100微摩尔/升的氨基葡萄糖浓度。
使用配备高灵敏度万通-峰仪器的高效液相色谱法对人血清氨基葡萄糖进行脉冲安培检测；在血清1:10稀释时0.5微摩尔/升的检测限使得能够测量人血清中低水平的氨基葡萄糖，而此前这是无法做到的。
18名骨关节炎患者在禁食过夜后服用1500毫克市售硫酸氨基葡萄糖，然后在基线时以及3小时内每15 - 30分钟采集一次血清，另外，从两名受试者在5小时和8小时时采集血清。从三名受试者在基线时和摄入后3小时收集尿液样本。
所有受试者的基线氨基葡萄糖均低于0.5微摩尔/升的检测限，但摄入后，18名受试者中有17名检测到氨基葡萄糖，在30 - 45分钟开始上升，在90 - 180分钟达到最大值，范围为1.9 - 11.5微摩尔/升（0.34 - 2微克/毫升）。
先前已表明，这11.5微摩尔/升的最大浓度在氨基葡萄糖与培养的人软骨细胞孵育时，对掺入硫酸软骨素的半乳糖胺的贡献小于2%，且该浓度远低于其他研究者声称具有各种显著体外效应的氨基葡萄糖浓度。这引发了对基于氨基葡萄糖在高得多浓度下的体外效应而使用氨基葡萄糖的当前生物学原理的质疑。
