Document Detail

Norepinephrine increases beta-receptors and adenylate cyclase in canine myocardium.
MedLine Citation:
PMID:  6320666     Owner:  NLM     Status:  MEDLINE    
Norepinephrine, a known inducer of myocardial hypertrophy, was found to have marked effects on the myocardial adrenergic system, which occurred prior to the development of a significant increase in heart weight. The chronic subhypertensive infusion (1.4 microgram/min) in free-roaming dogs produced a threefold increase in plasma norepinephrine (determined by radioimmunoassay). After 3 mo of infusion, right and left ventricular norepinephrine content (ng/mg protein) decreased significantly by twofold (right, 2.50 +/- 0.24; left, 2.08 +/- 0.36) compared with controls (right, 4.76 +/- 1.48; left, 4.65 +/- 1.49), and beta-receptor density (125I-pindolol) increased (right, 0.122 +/- 0.029; left, 0.153 +/- 0.021) over the controls (right, 0.082 +/- 0.015; left, 0.069 +/- 0.008 pmol/mg protein). Accompanying the beta-receptor changes, isoproterenol-stimulated adenylate cyclase activity also increased significantly [right, 29.2 +/- 2.1; left, 29.5 +/- 1.0 vs. controls, right, 13.8 +/- 1.1; left, 20.2 +/- 2.2 pmol adenosine 3',5'-cyclic monophosphate (cAMP) generated X min-1 X mg protein-1]. Because the above changes occurred in the absence of cardiac hypertrophy, it suggests that alterations in the myocardial adrenergic system are dependent on the stimulus (in this case norepinephrine) invoking the change and not the degree of hypertrophy. It also suggests that changes in the adrenergic system may not directly reflect the mechanism involved in the development of hypertrophy.
W J Raum; M M Laks; D Garner; M H Ikuhara; R S Swerdloff
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The American journal of physiology     Volume:  246     ISSN:  0002-9513     ISO Abbreviation:  Am. J. Physiol.     Publication Date:  1984 Jan 
Date Detail:
Created Date:  1984-03-07     Completed Date:  1984-03-07     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370511     Medline TA:  Am J Physiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  H31-6     Citation Subset:  IM    
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MeSH Terms
Adenylate Cyclase / metabolism*
Cardiomegaly / chemically induced,  metabolism
Cyclic AMP / metabolism
Heart / drug effects
Isoproterenol / pharmacology
Myocardium / metabolism*
Norepinephrine / pharmacology*
Receptors, Adrenergic, beta / drug effects*,  metabolism
Reg. No./Substance:
0/Receptors, Adrenergic, beta; 51-41-2/Norepinephrine; 60-92-4/Cyclic AMP; 7683-59-2/Isoproterenol; EC Cyclase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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