Shirasaki, Y., Yoshioka, N., Kanazawa, K. et al. 2011. Effect of physical restraint on glucose tolerance in cynomolgus monkeys. American Association for Laboratory Animal Science [AALAS] Meeting Official Program, 818 (Abstract #P328).

Physiologic stress has been demonstrated to impair glucose tolerance and insulin action. In the present study, we examined whether glucose tolerance is influenced by restraint stress. Studies were designed using female cynomolgus monkeys (3.2 to 4.6 kg) with normal glucose tolerance and impaired glucose tolerance (IGT), all of which were well trained to the restraint procedures, including chair restraint, hand restraint, and the restraint of animals in a home cage using a squeezing device. Oral glucose tolerance tests (OGTT) were performed by administration of glucose (4 g/kg). Blood was collected at 0, 15, 30, 60, 120, and 180 min after the glucose load. Each group underwent 4 to 5 trials of OGTT and there were at least 7 d between each trial. Since monkeys that were adequately trained to physical restraints were used, behavioral changes such as aggression and agitation were not observed during OGTT. In monkeys with IGT, chair restraint induced a significant increase in plasma glucose following a glucose challenge, and reached maxima of more than 150 mg/dL. The overall glucose excursion in chair-restrained subjects was significantly higher than that in hand-restrained or squeezing device-restrained subjects. Furthermore, chair-restrained subjects had high levels of plasma cortisol, a stress marker, during OGTT compared with handrestrained subjects. Similar results were obtained in monkeys with normal glucose tolerance; chair-restrained subjects elicited higher elevations of plasma glucose and cortisol compared with squeezing device-restrained subjects. Thus, we found that the responses to a glucose challenge are different among restraint procedures. Given that chair restraint imposes higher stress levels to subjects compared with other restraint procedures, we conclude that the high glucose excursion induced by chair restraint is attributed, at least in part, to the increase in plasma cortisol levels.