Stimulatory effect of naloxone on plasma cortisol in human: Possible direct stimulatory action at the adrenal cortex.
The purpose of the present study was to gain a better insight in the mechanism of naloxone underlying the regulation of adrenal cortisol secretion in humans in vivo; therefore, the stimulatory effect of naloxone on cortisol secretion was assessed in a group of patients with hypothalamo-pituitary disconnection. Patients with hypothalamo-pituitary disconnection because of various pathologies (craniopharingioma, cordoma, suprasellar meningioma, or pituitary macroadenoma) participated in the study.


RESULTS
Circulating cortisol, but not adrenocorticotropin (ACTH) levels were significantly higher after naloxone administration than after saline.


CONCLUSIONS
Besides the well-known hypothalamo-pituitary stimulatory action on ACTH release in normal humans, the results of the present study suggest that naloxone exerts direct effects on cortisol secretion at the adrenal gland level; another possibility is that naloxone stimulation of cortisol secretion is mediated by other factor than ACTH.
Coiro
V
V
Dept. of Internal Medicine and Biomedical Sciences, University of Parma, Parma, Italy. vittorio.coiro@unipr.it
Volpi
R
R
Stella
A
A
Venturi
N
N
Chiodera
P
P
D000302:Adrenal Cortex / Q000187:drug effects*; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism; D000328:Adult; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood* / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009270:Naloxone / Q000494:pharmacology*; D010911:Pituitary Neoplasms / Q000097:blood
D009270:Naloxone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone