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

Journal Article · Thu Mar 01 00:00:00 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), Vol. 15:3; ISSN 0160-2446
• Country of Publication: United States
• Language: English

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