Hayes R D, Beach J R, Rutherford D M, Sim M R
Dept of Epidemiology and Preventive Medicine, Monash Medical School, Melbourne, Australia.
Eur Respir J. 1998 Apr;11(4):946-8. doi: 10.1183/09031936.98.11040946.
Methacholine chloride solutions, routinely used for testing bronchial hyperreactivity, have been shown to degrade over time. The data published addressing the optimal conditions for methacholine chloride storage are conflicting and incomplete. This study investigated the effects of a variety of conditions on the stability of methacholine chloride. Methacholine chloride, dissolved in phosphate buffered saline (PBS) or sodium chloride (NaCl) at 50 and 0.39 g x L(-1), was subjected to various light and temperature conditions for 9 months. Methacholine chloride degradation was determined by high performance liquid chromatography, and all solutions underwent bacterial and pH testing. By 9 months, all 50 g x L(-1) solutions of methacholine chloride had degraded by 65+/-0.8%. All 0.39 g x L(-1) solutions in NaCl had degraded by 11.0+/-0.33%. The 0.39 g x L(-1) solutions in PBS which had been frozen, refrigerated or stored at room temperature had degraded by 8.0%, 16.0+/-0.3% and 63.8+/-0.5%, respectively. The pH of methacholine chloride was 7.2 in PBS at 0.39 g x L(-1), 5.8 in PBS at 50 g x L(-1), 3.9 in NaCl at 0.39 and 2.7 in NaCl at 50 g x L(-1). Bacterial contamination was minimal. The results of this study demonstrate that methacholine chloride is more stable at the higher concentration. However, the pH of the more concentrated solutions of methacholine chloride in sodium chloride could cause bronchoconstriction in some subjects. We therefore recommend storing methacholine chloride at 50 g x L(-1) in phosphate-buffered saline.
常用于检测支气管高反应性的氯化乙酰甲胆碱溶液已被证明会随时间降解。已发表的关于氯化乙酰甲胆碱储存最佳条件的数据相互矛盾且不完整。本研究调查了多种条件对氯化乙酰甲胆碱稳定性的影响。将溶解于磷酸盐缓冲盐水（PBS）或氯化钠（NaCl）中浓度分别为50和0.39 g·L⁻¹的氯化乙酰甲胆碱置于各种光照和温度条件下9个月。通过高效液相色谱法测定氯化乙酰甲胆碱的降解情况，所有溶液均进行了细菌和pH值检测。到9个月时，所有50 g·L⁻¹的氯化乙酰甲胆碱溶液降解了65±0.8%。所有0.39 g·L⁻¹溶解于NaCl中的溶液降解了11.0±0.33%。溶解于PBS中0.39 g·L⁻¹的溶液，经冷冻、冷藏或室温储存后，降解率分别为8.0%、16.0±0.3%和63.8±0.5%。0.39 g·L⁻¹溶解于PBS中的氯化乙酰甲胆碱pH值为7.2，50 g·L⁻¹溶解于PBS中的为5.8，0.39 g·L⁻¹溶解于NaCl中的为3.9，50 g·L⁻¹溶解于NaCl中的为2.7。细菌污染极少。本研究结果表明，氯化乙酰甲胆碱在较高浓度时更稳定。然而，在氯化钠中浓度较高的氯化乙酰甲胆碱溶液的pH值可能会在某些受试者中引起支气管收缩。因此，我们建议将氯化乙酰甲胆碱以50 g·L⁻¹的浓度储存在磷酸盐缓冲盐水中。
