Opioid peptides in response to mental stress in asymptomatic dilated cardiomyopathy

• Published in: Peptides (New York, N.Y. : 1980) Vol. 19; no. 7; pp. 1147 - 1153
• Main Authors: Fontana, Fiorella, Bernardi, Pasquale, Pich, Emilio Merlo, Tartuferi, Lucia, Boschi, Stefano, De Iasio, Rosaria, Spampinato, Santi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.1998
• Subjects: Atrial natriuretic factor; Atrial Natriuretic Factor - blood; beta-Endorphin - blood; Blood Pressure - drug effects; Cardiomyopathy, Dilated - blood; Cardiomyopathy, Dilated - complications; Cardiomyopathy, Dilated - physiopathology; Dilated cardiomyopathy; Dynorphin B; Dynorphins - blood; Endorphins - blood; Endothelin-1; Endothelin-1 - blood; Enkephalin, Methionine - blood; Female; Heart Rate - drug effects; Humans; Intelligence Tests; Male; Mathematics; Mental arithmetic test; Met-enkephalin; Middle Aged; Naloxone; Naloxone - pharmacology; Narcotic Antagonists - pharmacology; Norepinephrine; Norepinephrine - blood; Opioid Peptides - blood; Stress, Psychological - blood; Stress, Psychological - complications; β-endorphin; Naloxone; Dilated cardiomyopathy; Endothelin-1; Met-enkephalin; β-endorphin; Norepinephrine; Dynorphin B; Mental arithmetic test; Atrial natriuretic factor
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/S0196-9781(98)00073-4

Fourteen asymptomatic dilated cardiomyopathy patients showing normal plasma levels of β-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 sympatho-adrenergic hyperactivity, may further increase the sympathetic tone in a positive feedback that is interrupted by naloxone.