The effects of right stellate ganglion stimulation (RSGS) on regional myocardial blood flow (RMBF) and epicardial ST-segment elevation were investigated in the normal and ischemic myocardium of anesthetized dogs. In the non-ischemic areas and despite the augmentation of cardiac work resulting from the increase in heart rate and in myocardial contractile force, RSGS induced no significant changes in RMBF or in the endo/epi ratio. However, after suppression by atenolol of its chronotropic and inotropic effects, RSGS significantly increased the calculated coronary resistance and reduced RMBF, and combined atenolol + phenoxybenzamine treatments abolished these effects. In the ischemic areas, RSGS had no effect on RMBF, endo/epi and I/NI ratios but increased ST-segment elevation, an effect abolished by atenolol. We conclude that (1) during RSGS, alpha-adrenoreceptor-mediated coronary vasoconstriction contributes to oppose beta 1-myocardial stimulation effects on RMBF and endo/epi ratio, (2) further elevation of ST-segment by RSGS is due to enhancement of oxygen requirements by beta 1-adrenoreceptor stimulation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0014-2999(81)90025-x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Coronary sinus occlusion enhances coronary collateral flow and reduces subendocardial ischemia.
Am J Physiol Heart Circ Physiol
March 2001
First Department of Internal Medicine, Asahikawa Medical College, Asahikawa 078-8510, Japan.
On the hypothesis that coronary sinus occlusion (CSO) may reduce myocardial ischemia, we examined the effects of CSO on coronary collateral blood flow and on the distribution of regional myocardial blood flow (RMBF) in dogs. Thirty-eight anesthetized dogs underwent occlusion of the left anterior descending coronary artery with or without CSO and intact vasomotor tone. We measured RMBF and intramyocardial pressure (IMP) in the subendocardium (Endo) and subepicardium (Epi) separately.
View Article and Find Full Text PDFValidation of a subendocardial ischaemic sheep model by intracoronary fluorescent microspheres.
Clin Exp Pharmacol Physiol
February 1996
Department of Medicine, Clinical School, University of Tasmania, Hobart, Australia.
1. We evaluated the use of non-radioactive fluorescent-labelled microspheres (FM) for the measurement of regional myocardial blood flow (RMBF) in an ischaemic sheep model. 2.
View Article and Find Full Text PDFSystemic and coronary effects of the angiotensin II receptor antagonist EXP3174 in dogs.
J Cardiovasc Pharmacol
July 1993
Département de Pharmacologie, Faculté de Médecine Paris Sud, Le Kremlin-Bicêtre, France.
The effects of EXP3174 (0.03-0.3 mg/kg), the active metabolite of the angiotensin II (AII) receptor antagonist losartan, on systemic and coronary hemodynamics as well as on regional myocardial blood flow (radioactive microspheres) were evaluated in anesthetized, open-chest dogs with or without preactivated renin-angiotensin system (RAS) (furosemide treatment).
View Article and Find Full Text PDFThe effects of propranolol alone or associated with atrial pacing were studied on regional myocardial blood flows (RMBF) and regional contractility (sonocardiometry) in non-ischemic, moderately and severely ischemic areas of the canine myocardium. In non-ischemic areas, propranolol reduced both epicardial and endocardial flows, increased the endo/epi ratio and decreased regional contractility. The reductions in subendocardial flow and function were correlated.
View Article and Find Full Text PDFThe effects of right stellate ganglion stimulation (RSGS) on regional myocardial blood flow (RMBF) and epicardial ST-segment elevation were investigated in the normal and ischemic myocardium of anesthetized dogs. In the non-ischemic areas and despite the augmentation of cardiac work resulting from the increase in heart rate and in myocardial contractile force, RSGS induced no significant changes in RMBF or in the endo/epi ratio. However, after suppression by atenolol of its chronotropic and inotropic effects, RSGS significantly increased the calculated coronary resistance and reduced RMBF, and combined atenolol + phenoxybenzamine treatments abolished these effects.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!