Twardowski Z J, Nolph K D, McGary T J, Moore H L, Collin P, Ausman R K, Slimack W S
Am J Hosp Pharm. 1983 Apr;40(4):575-9.
A radiotracer method to assess insulin binding to commercially available plastic peritoneal dialysis solution containers was developed. A peritoneal dialysis bag (bag 2) was emptied and attached to another full bag (bag 1) of the same kind. In the syringe-to-bag method, bag 1 was symmetrically injected through the bag wall with four syringes containing dialysis solution and radioactive insulin, with or without regular insulin. The radioactivity in each syringe was measured with a gamma counter before injection, and all of the samples were counted afterwards directly in the syringes. Using a bag-to-bag transfer method, bag 1 was agitated, eight samples were taken from different parts through the wall, and then the contents were transferred to bag 2. Bag 2 was then agitated and eight samples were taken and counted. In the bag-pieces method, pieces of bag wall were cut and the radioactivity on the walls was measured to determine the amount of binding. The syringe-to-bag method gave negative results, severely underestimating the amount of insulin binding. The bag-to-bag transfer method yielded positive results in all instances. Increasing the amounts of regular insulin had no demonstrable impact on percent of binding. When the bag-to-bag method was compared with the bag-pieces method, it gave only slightly higher values; however, the bag-to-bag method was considered more reliable because the counting can be controlled more effectively. A 15-minute delay in sampling was not found to influence insulin binding. A reliable method of assessing insulin binding must be based on the following two principles: (1) The transfer of samples to intermediate containers should be avoided, and (2) radiotracer concentrations in the samples should be similar.
开发了一种放射性示踪剂方法来评估胰岛素与市售塑料腹膜透析液容器的结合情况。将一个腹膜透析袋（袋2）排空并连接到另一个相同类型的满袋（袋1）上。在注射器对袋法中，用四个装有透析液和放射性胰岛素（有或没有常规胰岛素）的注射器通过袋壁对称地注入袋1。在注射前用γ计数器测量每个注射器中的放射性，之后所有样品直接在注射器中计数。使用袋对袋转移法，将袋1搅拌，通过袋壁从不同部位取八个样品，然后将内容物转移到袋2。然后搅拌袋2，取八个样品并计数。在袋片法中，切割袋壁的碎片并测量壁上的放射性以确定结合量。注射器对袋法得出阴性结果，严重低估了胰岛素结合量。袋对袋转移法在所有情况下都得出阳性结果。增加常规胰岛素的量对结合百分比没有明显影响。当将袋对袋法与袋片法进行比较时，它给出的值仅略高；然而，袋对袋法被认为更可靠，因为计数可以得到更有效的控制。发现采样延迟15分钟不会影响胰岛素结合。一种评估胰岛素结合的可靠方法必须基于以下两个原则：（1）应避免将样品转移到中间容器中，（2）样品中的放射性示踪剂浓度应相似。
