Morrow-Tesch, J. L., McGlone, J. J., Norman, R. L. 1993. Consequences of restraint stress on natural killer cell activity, behavior, and hormone levels in rhesus macaques (Macaca mulatta). Psychoendocrinology 18, 383-395.

Animals were chair restrained and samples taken after 1, 2 and 3 hours. WBC and the percentage of neutrophils increased during the restraint period, while the percent lymphocytes and monocytes decreased. NK [natural killer cell] activity also decreased over time after restraint whereas plasma cortisol and endorphin levels increased significantly.