Reduced ACTH/cortisol responses to naloxone in men with Parkinson's disease.
In order to establish whether the inhibitory control exerted by endogenous opioid peptides on ACTH/cortisol secretion changes in patients affected by Parkinson's disease, ten parkinsonian male subjects and eight age matched normal controls were tested with naloxone (4 mg an i.v. bolus plus 10 mg infused in two hours). In a different occasion all subjects were tested with normal saline. Experiments started at 09.00 h. Plasma ACTH and cortisol concentrations showed a slight physiological decline during saline test in both groups. In the normal controls and in the parkinsonian patients both ACTH and cortisol levels were significantly higher after naloxone administration than during saline test. However, both naloxone induced ACTH and cortisol responses were significantly higher in normal than in parkinsonian subjects. In agreement with the well-known opioid deficiency characterizing the parkinsonian brain, these data show a reduced opioid inhibitory control of ACTH/cortisol secretion in patients with Parkinson's disease.
Volpi
R
R
Chair of Medical Clinic, University of Parma, Italy.
Caffarra
P
P
Marcato
A
A
Scaglioni
A
A
Maestri
D
D
Delsignore
R
R
Chiodera
P
P
Coiro
V
V
D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism*; D000368:Aged; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009270:Naloxone; D010300:Parkinson Disease / Q000097:blood* / Q000503:physiopathology; D012016:Reference Values; D013997:Time Factors
D009270:Naloxone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone