Opioid peptides in response to mental stress in asymptomatic dilated cardiomyopathy.
Fourteen asymptomatic dilated cardiomyopathy patients showing normal plasma levels of beta-endorphin, Met-enkephalin, dynorphin B, norepinephrine and endothelin-1 but elevated atrial natriuretic factor (ANF) levels underwent two Mental Arithmetic Tests (MAT), with placebo and naloxone hydrochloride infusion, respectively. MAT significantly (p < 0.01) increased blood pressure, heart rate, opioid peptides, norepinephrine, ANF, but not endothelin-1. Naloxone infusion significantly (p < 0.05) attenuated the increments produced by MAT in all measured parameters during placebo infusion. These results indicate that in asymptomatic dilated cardiomyopathy the endogenous opioid system, activated by stress-induced sympathoadrenergic hyperactivity, may further increase the sympathetic tone in a positive feedback that is interrupted by naloxone.
Fontana
F
F
Dipartimento di Medicina Interna, Cardioangiologia, Epatologia, Ospedale S. Orsola, Bologna, Italy.
Bernardi
P
P
Merlo Pich
E
E
Tartuferi
L
L
Boschi
S
S
De Iasio
R
R
Spampinato
S
S
D009320:Atrial Natriuretic Factor / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D002311:Cardiomyopathy, Dilated / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D004399:Dynorphins / Q000097:blood; D004723:Endorphins / Q000097:blood; D019332:Endothelin-1 / Q000097:blood; D004744:Enkephalin, Methionine / Q000097:blood; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D009270:Naloxone / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D009638:Norepinephrine / Q000097:blood; D018847:Opioid Peptides / Q000097:blood*; D013315:Stress, Psychological / Q000097:blood* / Q000150:complications; D001615:beta-Endorphin / Q000097:blood
D004723:Endorphins; D019332:Endothelin-1; D009292:Narcotic Antagonists; D018847:Opioid Peptides; D009270:Naloxone; D004744:Enkephalin, Methionine; D001615:beta-Endorphin; D004399:Dynorphins; C036200:rimorphin; D009320:Atrial Natriuretic Factor; D009638:Norepinephrine