Journal article
Area postrema and differential reflex effects of vasopressin and phenylephrine in rats
American journal of physiology. Heart and circulatory physiology, Vol.258(4), pp.H1255-H1259
04/01/1990
DOI: 10.1152/ajpheart.1990.258.4.H1255
PMID: 2331015
Abstract
In normal rats, baroreflex inhibitions of heart rate (HR) and splanchnic but not lumbar sympathetic neural activity (SNA) are greater when mean arterial pressure (MAP) is increased by intravenous infusion of arginine vasopressin (AVP) compared with phenylephrine (PE) or methoxamine. In normal rabbits, baroreflex inhibitions of HR and lumbar and renal SNA are all greater when MAP is increased by AVP vs. PE. The differential reflex bradycardic and renal sympathoinhibitory effects of AVP vs. PE in rabbits require an intact area postrema. To determine whether differential reflex effects of AVP vs. PE in rats is selective for HR or inclusive of renal SNA and to examine the role of the rat area postrema in such action, we monitored HR and renal SNA in normal (sham operated, n = 8) and area postrema-lesioned (APX, n = 8) rats under chloralose anesthesia during slow increases in MAP (less than 0.3 mmHg/s; 3 min) induced intravenously by AVP (0-16 mU.kg-1.min-1) and by PE (0-8 micrograms.kg-1.min-1). Reflex inhibition of HR (-delta betas.min-1.delta mmHg-1) was greater when MAP was increased by AVP vs. PE in normal rats (-2.7 +/- 0.5 vs. -1.7 +/- 0.1, P less than 0.05), and this difference was absent in APX rats (-2.5 +/- 0.5 vs. +/- -2.2 +/- 0.4). Similarly, maximum bradycardia (-delta beats/min) by AVP vs. PE was greater in normal rats (-64 +/- 8 vs. -48 +/- 7, P less than 0.05) but not in APX rats (-53 +/- 5 vs. -52 +/- 6).
Details
- Title: Subtitle
- Area postrema and differential reflex effects of vasopressin and phenylephrine in rats
- Creators
- Jacob D Peuler - Veterans Administration Medical Center, Iowa City, IowaGaylen L Edwards - Veterans Administration Medical Center, Iowa City, IowaPhillip G Schmid - Veterans Administration Medical Center, Iowa City, IowaAlan Kim Johnson - Veterans Administration Medical Center, Iowa City, Iowa
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Heart and circulatory physiology, Vol.258(4), pp.H1255-H1259
- DOI
- 10.1152/ajpheart.1990.258.4.H1255
- PMID
- 2331015
- ISSN
- 0363-6135
- eISSN
- 1522-1539
- Language
- English
- Date published
- 04/01/1990
- Academic Unit
- Psychological and Brain Sciences; Cardiovascular Medicine; Neuroscience and Pharmacology; Health and Human Physiology; Internal Medicine
- Record Identifier
- 9984213271602771
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