ANP potentiates nonarterial baroreflex bradycardia: Evidence from sinoaortic denervation in rats

Abstract

Previous findings indicate that atrial natriuretic peptide (ANP) enhances the reflex bradycardia arising from stimulation of cardiac mechanoreceptors and chemoreceptors, but not that from arterial baroreceptors. The present study tests this proposal by examining the effect of ANP on these reflexes in six chronically sinoaortic-denervated (SAD), and eight sham-operated (sham), conscious rats. Arterial baroreceptor-heart rate (HR) reflex function was examined by constructing full-range steady-state blood pressure (BP)-HR curves using alternating doses of pressor (methoxamine, 2-100 μg/kg) and depressor (nitroprusside, 1-50 μg/kg) agents. Nonarterial baroreceptor reflex function was assessed by..