| Abstract: | Plasma insulin and glucose levels were simultaneously determined in 60 fasting raptors (seven species) which had experienced mild or severe stress: prolonged confinement in flight cages (Type A), and serious debilities such as fractured bones, soft-tissue damage and/or starvation (Type B) respectively. Two of the species contained Types A and B (43 birds) while the remaining five species (17 birds) were of Type B only. Wide ranges in plasma insulin (0-135 pg/ml or 0-3.0 microU/ml) were observed in both Types A and B. Mean levels were not significantly different between species, although levels in Type B tended to be lower than those in Type A. Wide ranges in plasma glucose (195-485 mg/dl) were also observed in Types A and B but mean levels between species were remarkably similar, and likewise were not significantly different. However, even though mean insulin and glucose levels did not differ significantly between mildly or severely stressed and fasting birds, a low-level but significant (P less than 0.001) correlation (r = 0.5772) between insulin and glucose levels existed. This suggests that insulin contributes minimally, but significantly, to regulation of plasma glucose levels during stressful experiences or the fasting state. |
