Research Paper Volume 9, Issue 5 pp 1375—1385

A decline in female baboon hypothalamo-pituitary-adrenal axis activity anticipates aging

Figure 2. Female baboon (P. hamadryas) linear regression of serum cortisol by age. (A) 24 baboons from the colony at Southwest National Primate Research Center (cortisol = -24.7*X+735.1 ng/ml; P=0.0007); (B) 31 baboons from the Oklahoma University Primate Center (colony cortisol = -23.7*X+1521; P=0.039). The data for the Oklahoma baboons are reproduced from their publication (Willis et al. 2014). Red symbols represent five baboons that were included in the immunohistochemistry studies reported here.