Szczudlik A, Lypka A, Kwasucki J, Foss A
Neurol Neurochir Pol. 1980 Jul-Aug;14(4):359-64.
Using a diagnostic kit N.E.N. (USA) the authors investigated beta-endorphin-like immunoreactivity in the plasma of young, healthy subjects. It was found that the level of beta-endorphin determined in this way in 10 subjects ranged from 15 to 120 pgml-1 and showed relatively constant values in two determinations carried out at an interval of one hour. Psychological tests showed that subjects with low beta-endorphin level had a low neuroticism index and extra-version, while in the subjects with high beta-endorphin level the neuroticism index was high and introversion features were more prevalent. After application of a painful stimulus (ischaemic test) the level of beta-endorphin changed in most subjects increasing or decreasing. The comparison of the differences in the levels of beta-endorphin immediately before and after the test for pain tolerance suggests that the higher was this difference the lower was pain tolerance and conversely.
作者使用美国N.E.N.公司的诊断试剂盒，对年轻健康受试者血浆中的β-内啡肽样免疫反应性进行了研究。结果发现，用这种方法测定的10名受试者的β-内啡肽水平在15至120 pg/ml-1之间，并且在间隔一小时进行的两次测定中显示出相对稳定的值。心理测试表明，β-内啡肽水平低的受试者神经质指数和外向性较低，而β-内啡肽水平高的受试者神经质指数较高，内向性特征更为普遍。在施加疼痛刺激（缺血试验）后，大多数受试者的β-内啡肽水平发生了变化，升高或降低。对疼痛耐受性测试前后β-内啡肽水平差异的比较表明，这种差异越大，疼痛耐受性越低，反之亦然。
