Diurnal rhythm of plasma catecholamines in acromegaly.
We investigated the 24-h profiles of the circulating levels of norepinephrine (NE) and epinephrine (E), blood pressure (BP), and heart rate in 14 acromegalic patients, before (A) and 3-6 months after transsphenoidal surgery (C-A, cured; A-A, active), and in 8 age-matched normal subjects (N). In addition, the responses of NE, E, PRA, and aldosterone to upright posture were investigated. No significant differences in the mean 24-h plasma NE and E levels were observed between either group of acromegalics and the N subjects. Analysis of the 24-h profiles indicated a statistically significant 24-h rhythm of both NE and E in N subjects. No evidence of a 24-h rhythm of plasma NE and E and BP was found in A patients. After surgery, a statistically significant 24-h rhythm of NE was detected in the patients with acrophase (13.54 and 13.45 h in C-A and A-A patients, respectively) and mesor (1019.8+/-45.1 and 1017.8+/-54.7 pmol/L in C-A and A-A patients, respectively) similar to those observed in N subjects (acrophase, 13.21 h; mesor, 942.3+/-42.5 pmol/L). After surgery, the plasma concentration of E clearly fluctuated throughout the 24 h in both C-A and A-A patients, even if cosinor analysis failed to reveal a 24-h significant rhythm. A statistically significant 24-h rhythm of BP was restored only in C-A patients. The mean 24-h heart rate was slightly, but significantly (P<0.05), higher in A than in N subjects and decreased after surgery. No significant differences in upright-stimulated NE, E, and plasma aldosterone levels were observed between each group of acromegalics and N subjects. However, basal and upright-stimulated PRA levels were significantly (P<0.001) lower in A patients. In conclusion, our study demonstrates the lack of a clear circadian variation in catecholamine levels and BP in active acromegaly and the return of a significant 24-h rhythm of NE and BP after pituitary surgery, concomitant with the reduction in GH and insulin-like growth factor I serum levels.
Bondanelli
M
M
Department of Biomedical Sciences and Advanced Therapies, University of Ferrara, Italy.
Ambrosio
M R
MR
Franceschetti
P
P
Margutti
A
A
Trasforini
G
G
Degli Uberti
E C
EC
D000172:Acromegaly / Q000097:blood* / Q000503:physiopathology / Q000601:surgery; D000328:Adult; D000450:Aldosterone / Q000097:blood; D001794:Blood Pressure; D002940:Circadian Rhythm; D004837:Epinephrine / Q000097:blood*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood*; D011187:Posture; D012083:Renin / Q000097:blood
D000450:Aldosterone; D012083:Renin; D009638:Norepinephrine; D004837:Epinephrine