Localization of beta-adrenergic receptors in transmural slices of myocardium with quantitative autoradiography

Conference · Sat Mar 01 00:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5495477

Murphree, S S; Saffitz, J E

Alterations in the density of myocardial ..beta..-adrenergic receptors (..beta..AR) induced by ischemia may be important in the pathophysiology of acute ischemic heart disease. Conventional binding assays in tissue homogenates lack the anatomic resolution required for cell-specific analysis of early alterations in receptor density induced by ischemia. Accordingly, the authors have developed methods for localization of ..beta..AR in transmural slices of feline left ventricle with quantitative autoradiography. Frozen sections were incubated with /sup 125/I-iodocyanopindolol (ICYP) +/- Z-propranolol for 60 min at 37/sup 0/. Non-specifically bound radioactivity was removed by rinsing the sections for 60 min at 22/sup 0/. At saturating concentrations of ICYP, > 90% specific binding was achieved. Specific binding was rapid, saturable, of high affinity and proportional to section thickness (B/sub max/ = 26.5 +/- 6.4 fmol/mg tissue protein; K/sub d/ = 10.0 +/- 2.1 pM; N = 14). Agonist binding showed the rank order of potency expected for ..beta..AR (IC/sub 50/ = 0.12 ..mu..M, isoproterenol; .18 ..mu..M, norepinephrine; .54 ..mu..M, epinephrine) and demonstrated stereo-selectivity (IC/sub 50/ = .013 ..mu..M, Z-isoproterenol; 9.5 ..mu..M, d-isoproterenol). Quantitative autoradiography with both film and emulsion methods will permit regional analysis of ..beta..AR density in large transmural sections as well as cell-specific analysis at the microscopic level.

• Research Organization: Washington Univ., St. Louis, MO
• OSTI ID: 5495477
• Report Number(s): CONF-8604222-; TRN: 86-026732
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ISCHEMIA
PATHOGENESIS
RECEPTORS
BIOLOGICAL LOCALIZATION
SYMPATHOMIMETICS
AFFINITY
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
IODINE 125
MYOCARDIUM
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DISEASES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HEART
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPES
KINETICS
MEMBRANE PROTEINS
MUSCLES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
VASCULAR DISEASES
550901* - Pathology- Tracer Techniques