This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by King, B. D. Articles by Hintze, T. H. Search for Related Content PubMed PubMed Citation Articles by King, B. D. Articles by Hintze, T. H.

Hypertension, Vol 9, 582-590, Copyright © 1987 by American Heart Association

ARTICLES

Absence of hypertension despite chronic marked elevations in plasma norepinephrine in conscious dogs

BD King, D Sack, MR Kichuk and TH Hintze

To better define the mechanisms of blood pressure control in states of catecholamine excess, we infused norepinephrine for 28 days using subcutaneously implanted osmotic pumps in dogs previously instrumented for monitoring left ventricular dynamics and cardiac output. Plasma norepinephrine rose from 238 +/- 27 to 4346 +/- 952 pg/ml at 21 days, while epinephrine and dopamine levels did not change. Heart rate fell from 85 +/- 4 to 63 +/- 6 beats/min, while arterial pressure was unchanged from baseline. Total peripheral resistance rose 0.011 +/- 0.003 mm Hg/ml/min from a control value of 0.029 +/- 0.002 mm Hg/ml/min, and cardiac output decreased 1093 +/- 292 ml/min from a baseline level of 3575 +/- 156 ml/min. Since stroke volume did not change, the maintenance of arterial pressure is related to decreases in cardiac output secondary to bradycardia. Buffering mechanisms are responsible for maintenance of systemic arterial pressure because hexamethonium and atropine caused hypertension. Although left ventricular end-diastolic pressure, end-diastolic diameter, shortening, rate of change of pressure, velocity of myocardial shortening, cardiac work, stroke work, and the double product did not change significantly during the study, postmortem examination demonstrated biventricular hypertrophy. Thus, despite markedly elevated catecholamine levels and no elevation of systemic arterial pressure, myocardial hypertrophy developed. These studies lend support to the hypothesis that norepinephrine may be a direct myocardial tropic hormone and suggest that intense activation of reflex buffering mechanisms maintains blood pressure in the normal range during chronic catecholamine infusion.

This article has been cited by other articles:

				R. Ramchandra, C. J. Barrett, and S. C. Malpas Chronic Blockade of Nitric Oxide Does Not Produce Hypertension in Baroreceptor Denervated Rabbits Hypertension, November 1, 2003; 42(5): 974 - 977. [Abstract] [Full Text] [PDF]

				R. Wadhawan, Y.-T. Tseng, J. Stabila, B. McGonnigal, S. Sarkar, and J. Padbury Regulation of cardiac beta 1-adrenergic receptor transcription during the developmental transition Am J Physiol Heart Circ Physiol, June 1, 2003; 284(6): H2146 - H2152. [Abstract] [Full Text] [PDF]

				P. Sipola, E. Vanninen, H. J. Aronen, K. Lauerma, S. Simula, P. Jaaskelainen, M. Laakso, K. Peuhkurinen, J. Kuusisto, and J. T. Kuikka Cardiac Adrenergic Activity Is Associated with Left Ventricular Hypertrophy in Genetically Homogeneous Subjects with Hypertrophic Cardiomyopathy J. Nucl. Med., April 1, 2003; 44(4): 487 - 493. [Abstract] [Full Text] [PDF]

				T. N. Thrasher Unloading arterial baroreceptors causes neurogenic hypertension Am J Physiol Regulatory Integrative Comp Physiol, April 1, 2002; 282(4): R1044 - R1053. [Abstract] [Full Text] [PDF]

				F. Qin, N. K. Rounds, W. Mao, K. Kawai, and C.-s. Liang Antioxidant vitamins prevent cardiomyocyte apoptosis produced by norepinephrine infusion in ferrets Cardiovasc Res, September 1, 2001; 51(4): 736 - 748. [Abstract] [Full Text] [PDF]

				Y. Du, J. Qiu, S. H. Nelson, and D. H. Wang Regulation of type 1 ANG II receptor in vascular tissue: role of alpha 1-adrenoreceptor Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1997; 273(4): R1224 - R1229. [Abstract] [Full Text] [PDF]

				D. H. Wang, J. Qiu, Z. Hu, and Y. Du Regulation of Type 1 Angiotensin II Receptor in Adrenal Gland : Role of {alpha}1-Adrenoreceptor Hypertension, September 1, 1997; 30(3): 345 - 350. [Abstract] [Full Text]

				T. Yamazaki, I. Komuro, Y. Zou, S. Kudoh, I. Shiojima, Y. Hiroi, T. Mizuno, R. Aikawa, H. Takano, and Y. Yazaki Norepinephrine Induces the raf-1 Kinase/Mitogen-Activated Protein Kinase Cascade Through Both {alpha}1- and ß-Adrenoceptors Circulation, March 4, 1997; 95(5): 1260 - 1268. [Abstract] [Full Text]