Faculty Collaboration Database

Role of autoregulation in the beneficial action of propranolol on ischemic blood flow distribution and stenosis severity in the canine myocardium. J Pharmacol Exp Ther 1982 Sep;222(3):635-40

Date

09/01/1982

Pubmed ID

7108768

Scopus ID

2-s2.0-0019988255 (requires institutional sign-in at Scopus site)   15 Citations

Abstract

The effect of propranolol (0.1 mg/kg i.v.) on distal coronary pressure (DCP), distal bed (DR) and stenosis resistances (SR) and regional myocardial blood flow [endocardial-epicardial (endo/epi)] was studied in two groups of anesthetized dogs with a severe stenosis of the left circumflex coronary artery. In group 1, the ability of the DR to autoregulate was left intact, whereas in group 2, the DR was maximally dilated by pretreatment with the coronary vasodilator, chromonar. Despite similar global hemodynamic effects in both groups after propranolol treatment significant differences were observed in the ischemic area. In group 1, propranolol produced a significant increase in subendo blood flow, endo/epi and DCP in the ischemic region. In addition, DR (1.7 +/- 0.4 to 3.3 +/- 0.6 U) increased and SR decreased (3.4 +/- 0.5 to 1.7 +/- 0.3 U) significantly. In group 2, the changes in endo/epi, DCP, DR and SR were prevented by maximal vasodilation. These results suggest that the favorable changes produced by propranolol on ischemic myocardium are the result of a restoration of the ability of the resistance vessels to autoregulate. This allows for a passive decrease in coronary arteriolar dilation which results in an increase in DR and DCP and a decrease in SR. The increase in DCP may also contribute to the increase in ischemic subendo blood flow after propranolol.

Author List

Gross GJ, Buck JD, Warltier DC, Hardman HF

Author

David C. Warltier PhD Emeritus Professor in the Anesthesiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Blood Pressure
Chromonar
Coronary Circulation
Coronary Disease
Coronary Vessels
Dogs
Female
Heart
Homeostasis
Male
Propranolol
Vascular Resistance