rimorphin and Cardiomyopathy--Dilated

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.

Topics: Atrial Natriuretic Factor; beta-Endorphin; Blood Pressure; Cardiomyopathy, Dilated; Dynorphins; Endorphins; Endothelin-1; Enkephalin, Methionine; Female; Heart Rate; Humans; Intelligence Tests; Male; Mathematics; Middle Aged; Naloxone; Narcotic Antagonists; Norepinephrine; Opioid Peptides; Stress, Psychological