Relationship between beta-adrenoceptors and coronary blood flow heterogeneity

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(89)90312-3· OSTI ID:6025049

Upsher, M E; Weiss, H R

The purpose of this study was to investigate the hypothesis that the heterogeneous distribution of ..beta.. adrenoceptors contributes to the control of flow heterogeneity in the canine myocardium. ..beta.. adrenoceptor density and affinity were measured simultaneously with coronary blood flow in multiple sections of the left ventricle of 14 anesthetized open chest dogs. Radioactive microspheres were used for the measurement of blood flow. Receptor density (Bmax) and dissociation constant (Kd) were measured using (/sup 125/I)- iodopindolol. The average control myocardial blood flow (MBF) was 86/+-/15 ml/min/100 g. Isoproterenol increased MBF by 82%, whereas propranolol reduced MBF by 13%. The mean value of Bmax was unaltered by either treatment. Under control conditions, a significant positive positive correlation was observed between Bmax and blood flow. In the isoproterenol treatment group, this correlation was enhanced. Beta adrenoceptor blockade led to a negative correlation. Kd showed no overall correlation with blood flow. Kd but not Bmax was significantly higher in the EPI than in the ENDO and in the base compared to the apex. There appears to be a direct linear relationship between the distribution of beta adrenoceptors and MBF distribution which is enhanced under conditions of high beta adrenergic activity. There is a correlation between beta adrenoceptor activity and blood flow distribution in the canine myocardium.

• Research Organization: Robert Wood Johnson Medical School, Piscataway, NJ (USA)
• OSTI ID: 6025049
• Journal Information: Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 44:17; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ARTERIES
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BLOOD FLOW
BLOOD VESSELS
BODY
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
CORONARIES
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
DOGS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HEART
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MEMBRANE PROTEINS
MICROSPHERES
MUSCLES
MYOCARDIUM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
RECEPTORS
SUBCELLULAR DISTRIBUTION
SYMPATHOMIMETICS
TRACER TECHNIQUES
VASODILATORS
VERTEBRATES