Journal article
Differential modulation of baroreflex control of heart rate by neuron- vs. glia-derived angiotensin II
Physiological genomics, Vol.20(1), pp.66-72
12/15/2004
DOI: 10.1152/physiolgenomics.00168.2004
PMID: 15467015
Abstract
We developed transgenic mice with targeted expression of human renin (hREN) and human angiotensinogen (hAGT) to either neurons (N-AII mice) or glia (G-AII mice) to test the hypothesis that neuronal and glial ANG II may have differential function. Since baseline blood pressure (BP) did not differ between the models (109 ± 3 vs. 114 ± 4 mmHg), we stressed the BP regulatory pathway by measuring the heart rate (HR) (baroreflex) response to phenylephrine- and nitroprusside-induced changes in arterial BP. The midpoint of the baroreflex curve (BP50) was reset to a significantly higher BP in N-AII mice (131 ± 5 mmHg) compared with littermate controls (115 ± 3 mmHg). Baroreflex gain (slope of BP-HR relation) was similar in N-AII and control mice (12 ± 1 vs. 14 ± 2 beats·min−1·mmHg−1). In contrast, G-AII mice exhibited less of an increase in BP50 (125 ± 5 mmHg) but a larger decrease in baroreflex gain (8 ± 1 beats·min−1·mmHg−1) compared with both control and N-AII mice. Differences in BP50 and gain between N-AII, G-AII, and control mice persisted after parasympathetic blockade with atropine but were eliminated after sympathetic blockade with propranolol, indicating the effects of ANG II were selective for cardiosympathetic arm of the reflex. ANG II-like immunoreactivity was observed more prominently around the paraventricular nucleus and nucleus tractus solitarii in G-AII mice but more prominently in the ventrolateral medulla in N-AII mice. We conclude that ANG II differentially modulates baroreflex control of HR in mice producing ANG II in neurons vs. glia, and its differential function may reflect regional differences in the production of ANG II in cardiovascular control nuclei of the brain.
Details
- Title: Subtitle
- Differential modulation of baroreflex control of heart rate by neuron- vs. glia-derived angiotensin II
- Creators
- Koji Sakai - Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IowaMark W Chapleau - Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, Veterans Affairs Medical Center, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, Department of Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IowaSatoshi Morimoto - Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IowaMartin D Cassell - Department of Anatomy and Cell Biology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IowaCurt D Sigmund - Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, Department of Physiology and Biophysics, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
- Resource Type
- Journal article
- Publication Details
- Physiological genomics, Vol.20(1), pp.66-72
- DOI
- 10.1152/physiolgenomics.00168.2004
- PMID
- 15467015
- ISSN
- 1094-8341
- eISSN
- 1531-2267
- Language
- English
- Date published
- 12/15/2004
- Academic Unit
- Molecular Physiology and Biophysics; Anatomy and Cell Biology; Cardiovascular Medicine; Fraternal Order of Eagles Diabetes Research Center; Neuroscience and Pharmacology; Internal Medicine
- Record Identifier
- 9984025675302771
Metrics
18 Record Views