Different pattern of association of beta-endorphin and cortisol responses to dextroamphetamine in postmenopausal women and young men

A negative correlation between plasma β-endorphin and cortisol responses to 0.15 mg/kg dextroamphetamine i.v. was found in a group of seven normal postmenopausal women, while the responses of the two hormones were positively correlated in nine normal young men. These results suggest that even though the adrenocorticotropic hormone (ACTH)-cortisol and β-endorphin are usually regulated by the same mechanism (both ACTH and β-endorphin are derived from proopiocortin), there are situations in which these systems can be associated in a different pattern. The elucidation of these situations may contribute to the understanding of regulatory mechanisms of the two systems.