AJP - Heart Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 257: H553-H562, 1989;
0363-6135/89 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zuckerman, B. D.
Right arrow Articles by Yin, F. C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zuckerman, B. D.
Right arrow Articles by Yin, F. C.

AJP - Heart and Circulatory Physiology, Vol 257, Issue 2 553-H562, Copyright © 1989 by American Physiological Society

ARTICLES

Aortic impedance and compliance in hypertensive rats

B. D. Zuckerman and F. C. Yin
Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.

We compared aortic impedance and compliance in normotensive control and hypertensive Wistar rats. Hypertension was induced by unilateral nephrectomy plus steroid and salt water administration. After at least 8 wk of sustained hypertension (tail-cuff systolic pressures greater than 172 mmHg), open-chest ascending aortic micromanometric pressures and electromagnetic flows were measured. We used a frequency-modulated pacing method to enhance the energy content of the pressure and flow signals at specific low frequencies and their multiples. Impedance spectra were calculated using both Fourier series and spectral analysis methods. Compliance was calculated from the low-frequency impedance moduli, assuming a windkessel model for the arterial system. During pentobarbital sodium anesthesia under baseline conditions, the hypertensive rats had higher total resistance (219,000 vs. 126,000 dyn.s.cm-5), higher characteristic impedance (7,334 vs. 5,377 dyn.s.cm-5), larger first zero crossing of impedance phase angle (13.9 vs. 10 Hz), larger ratio of backward to forward pressure waves (0.67 vs. 0.48), and lower compliance (0.00498 vs. 0.00720 ml/mmHg) than controls. The differences between the groups were eliminated when the blood pressures of the hypertensive rats were normalized by vasodilation with nitroprusside or when the control rats were made hypertensive by vasoconstriction with phenylephrine. Thus the hemodynamic alterations appear to be secondary to the increased blood pressure. These base-line differences and the responses to vasoactive drugs are similar to findings in humans, suggesting that this rat model is a good hemodynamic model of human hypertension.


This article has been cited by other articles:


Home page
 Exp. Biol. Med.Home page
K.-C. Chang, K.-L. Hsu, and Y.-Z. Tseng
Effects of Diabetes and Gender on Mechanical Properties of the Arterial System in Rats: Aortic Impedance Analysis
Experimental Biology and Medicine, January 1, 2003; 228(1): 70 - 78.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
J. T. Potts, K. P. McKeown, and A. A. Shoukas
Reduction in arterial compliance alters carotid baroreflex control of cardiac output in a model of hypertension
Am J Physiol Heart Circ Physiol, April 1, 1998; 274(4): H1121 - H1131.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
D. Curran-Everett, Y. Zhang, M. D. Jones Jr., and R. H. Jones
An improved statistical methodology to estimate and analyze impedances and transfer functions
J Appl Physiol, December 1, 1997; 83(6): 2146 - 2157.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
H. I. Chen and C. T. Hu
Endogenous nitric oxide on arterial hemodynamics: a comparison between normotensive and hypertensive rats
Am J Physiol Heart Circ Physiol, October 1, 1997; 273(4): H1816 - H1823.
[Abstract] [Full Text] [PDF]

Home page
 CirculationHome page
G. F. Mitchell, M. A. Pfeffer, P. V. Finn, and J. M. Pfeffer
Equipotent Antihypertensive Agents Variously Affect Pulsatile Hemodynamics and Regression of Cardiac Hypertrophy in Spontaneously Hypertensive Rats
Circulation, December 1, 1996; 94(11): 2923 - 2929.
[Abstract] [Full Text]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online