Different endothelin receptor affinities in dog tissues

Journal Article · Mon Dec 31 23:00:00 EST 1990 · Journal of Receptor Research; (United States)

DOI:https://doi.org/10.3109/10799899109066408· OSTI ID:5017625

Loeffler, B M.L.; Loehrer, W ^[1]

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1. Pharmaceutical Research Department, F. Hoffmann-La Roche Ltd., Basel (Switzerland)

Endothelin (ET) is a long-lasting potent vasoconstrictor-peptide. Here the authors report different binding affinities of endothelin-1 (ET-1) to ET-receptors of various dog tissues. Crude microsomal fractions were prepared after homogenisation of dog tissues in 50 mM Tris/HCl, 20 mM MnCl2, 1 mM EDTA, pH 7.4 by differential centrifugation. Aliquots of microsomal fractions (70 micrograms of protein) were incubated at 25 degrees C for 180 min in the presence of 20 pM 125I-ET-1 and various concentrations of cold ET-1. Four different ET-1 receptor binding affinities were found: adrenals, cerebrum, liver, heart, skeletal muscle and stomach microsomal membranes contained high affinity binding sites (Kd 50 - 80 pM, Bmax 60 - 250 fmol/mg). In cerebellum and spleen medium affinity ET-1 receptors (Kd 350 pM, Bmax 880 and 1200 fmol/mg respectively) were present. In comparison lung and kidney microsomes contained a low affinity ET-1 receptor (Kd 800 and 880 pM, Bmax 1600 and 350 fmol/mg). Receptors of even lower affinity were present in heart, intestine and liver microsomes with Kd values of 3 - 6 nM.

• OSTI ID: 5017625
• Journal Information: Journal of Receptor Research; (United States), Journal Name: Journal of Receptor Research; (United States) Vol. 11:1-4; ISSN 0197-5110; ISSN JRERD
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CELL CONSTITUENTS
CENTRIFUGATION
DAYS LIVING RADIOISOTOPES
DOGS
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INTERMEDIATE MASS NUCLEI
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IODINE 125
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ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MICROSOMES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
PROTEINS
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
RIBOSOMES
SEPARATION PROCESSES
SPECIFICITY
TISSUES
TRACER TECHNIQUES
ULTRACENTRIFUGATION
VERTEBRATES