Baroreflex-mediated bradycardia but not tachycardia is blunted peripherally by intravenous mu-opioid agonists.


OBJECTIVE We sought to test the hypothesis that an intravenous dose of H-Tyr-D-Arg-Phe-Lys-NH2, a highly mu-receptor selective opioid peptide, suppresses baroreflex sensitivity through a peripheral mechanism. STUDY DESIGN A transient change in mean arterial pressure was produced in chronically instrumented pregnant ewes by norepinephrine or sodium… (More)