Reoxygenation, but neither hypoxia nor intermittent ischemia, increases ( sup 125 I)endothelin-1 binding to rat cardiac membranes

Journal Article · Thu Mar 01 04:00:00 EST 1990 · Journal of Cardiovascular Pharmacology; (USA)

DOI:https://doi.org/10.1097/00005344-199003000-00014· OSTI ID:7008032

Liu, J J; Gu, X H; Casley, D J; Nayler, W G ^[1]

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1. Univ. of Melbourne, Heidelberg, Victoria (Australia)

Standard binding techniques were used to establish whether either hypoxia, reoxygenation, perfusion under acidotic conditions, or stunning of the myocardium resembles ischemia and postischemic reperfusion in increasing cardiac membrane ({sup 125}I)endothelin-1 (ET-1) binding site density (Bmax). Membranes from aerobically perfused rat hearts bound ({sup 125}I)ET-1 to a single population of sites, with an affinity (KD) of 0.093 +/- 0.004 nM and a Bmax of 98.8 +/- 5.2 fmol/mg of protein. Bmax was increased (p less than 0.01) after 30 min of global ischemia, and further increased upon reperfusion, without changes in KD or selectivity. Neither three 10 min episodes of ischemia separated by 15 min of perfusion, nor perfusion at pH 6.8 instead of 7.4, nor 60 min of hypoxia altered Bmax, KD, or selectivity. Reoxygenation after 60 min of hypoxia increased Bmax (p less than 0.01) and KD (p less than 0.01) without changing selectivity. These results are interpreted to mean that the ischemia-induced increase in Bmax for ({sup 125}I)ET-1 cannot be explained simply in terms of the ischemia-induced acidosis, or the accompanying reduction in tissue adenosine triphosphate and creatine phosphate.

• OSTI ID: 7008032
• Journal Information: Journal of Cardiovascular Pharmacology; (USA), Journal Name: Journal of Cardiovascular Pharmacology; (USA) Vol. 15:3; ISSN 0160-2446; ISSN JCPCD
• Country of Publication: United States
• Language: English

Related Subjects

550901* -- Pathology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ANOXIA
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
HEART
IN VITRO
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISCHEMIA
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
MUSCLES
MYOCARDIUM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PATHOGENESIS
PEPTIDES
PERFUSED ORGANS
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
TRACER TECHNIQUES
VASCULAR DISEASES
VERTEBRATES