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Do natriuretic peptides modify arterial baroreflexes in sheep?
Author(s) -
Thomas Colleen J.,
Woods Robyn L.
Publication year - 2004
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.2004.028233
Subject(s) - baroreflex , baroreceptor , medicine , phenylephrine , heart rate , endocrinology , reflex , natriuretic peptide , reflex bradycardia , blood pressure , atrial natriuretic peptide , mean arterial pressure , heart failure
While atrial and B‐type natriuretic peptides (ANP and BNP) have been shown to enhance reflex responses attributed to cardiac vagal afferents, their effects on arterial baroreceptor reflex function remain controversial. The actions of C‐type natriuretic peptide (CNP) in this regard are unknown. To clarify their actions on arterial baroreflexes, we tested whether i.v. infusions of ANP, BNP or CNP at 10 pmol kg −1 min −1 modified the steady‐state mean arterial blood pressure–heart rate (MAP–HR) relationship in conscious sheep. At this dose, all three natriuretic peptides are known to enhance the cardiac chemoreflex response to phenylbiguanide (Bezold‐Jarisch reflex). Sigmoid MAP–HR relationships were constructed from the steady‐state responses to alternating injections of vasopressor (phenylephrine, 1–15 µg kg −1 ) and vasodepressor agents (nitroprusside, 1–15 µg kg −1 ) in the absence and presence of infused ANP, BNP or CNP (tested in random order at least 1 week apart). No parameter of the steady‐state baroreflex relationship was significantly altered by infusion of any of the three natriuretic peptides. We conclude that in conscious sheep, normal arterial baroreceptor–HR reflex function prevails in the presence of moderate doses of ANP, BNP or CNP.