This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted 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 White, C. W. Articles by Zimmerman, T. J. Search for Related Content PubMed PubMed Citation Articles by White, C. W. Articles by Zimmerman, T. J.

Circulation, Vol 54, 890-895, Copyright © 1976 by American Heart Association

ARTICLES

Reduced cholinergic sinus node restraint in hyperthyroidism

CW White and TJ Zimmerman

The role of the cholinergic nervous system in the tachycardia of hyperthyroidism was investigated in this study of dogs made severely thyrotoxic by the administration of Na-L-thyroxine over a six to nine month period. Differences in heart rate between control and thyrotoxic unanesthetized dogs could be abolished by cumulative doses of intravenous atropine both before and after beta-adrenergic blockade with propranolol, and at submaximal as well as maximal heart rates. There were no differences in the heart rate response of control and thyrotoxic anesthetized dogs to vagal stimulation or to the selective injection of hypertonic saline or acetylcholine into the perfused sinus node artery. The results indicate that in addition to the direct effects of thyroid hormone on sinus node automaticity there is an abnormality in parasympathetic control of heart rate in hyperthyroidism. The data suggest that this abnormality is not due to a decreased responsiveness of the sinus node or an impaired release of the cholinergic neurotransmitter, but may reflect a reduction in cholinergic efferent activity in the thyrotoxic state.

This article has been cited by other articles:

				T. Nakano, T. Konishi, and H. Takezawa Vasospastic Angina in Thyrotoxicosis Case Reports Angiology, September 1, 1987; 38(9): 717 - 722. [Abstract] [PDF]

				N. J. DEMERATH III and R. H. WILLIAMS Civil Religion in an Uncivil Society The ANNALS of the American Academy of Political and Social Science, July 1, 1985; 480(1): 154 - 166. [Abstract]