Specific receptor for endothelin in cultured rat cardiocytes

Journal Article · Mon May 15 04:00:00 EDT 1989 · Biochemical and Biophysical Research Communications; (USA)

DOI:https://doi.org/10.1016/S0006-291X(89)80165-2· OSTI ID:5517071

Hirata, Y; Fukuda, Y; Yoshimi, H; Emori, T; Shichiri, M; Marumo, F ^[1]

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1. Tokyo Medical and Dental Univ. (Japan)

Specific binding sites for the endothelium-derived vasoconstrictor endothelin (ET) and its effect on cytosolic free Ca2+ concentrations (( Ca2+)i) were studied in a primary culture of cardiocytes from neonatal rats. Binding studies using {sup 125}I-labeled-porcine ET as a radioligand revealed the presence of a single class of high-affinity binding sites for ET in cardiocytes with an apparent Kd of 6-9 x 10(-10) M and a Bmax of 50,000-80,000 sites/cell. Neither various vasoconstrictors nor Ca2+-channel blockers affected the binding. Pretreatment with ET substantially reduced the total number of ET receptors without changing their affinity. ET dose-dependently increased (Ca2+)i in fura-2-loaded cardiocytes. These data indicate that cardiocytes have specific ET receptors that are controlled by a down-regulation mechanism, and that ET induces a receptor-mediated increase in (Ca2+)i in cardiocytes.

• OSTI ID: 5517071
• Journal Information: Biochemical and Biophysical Research Communications; (USA), Journal Name: Biochemical and Biophysical Research Communications; (USA) Vol. 160:3; ISSN BBRCA; ISSN 0006-291X
• Country of Publication: United States
• Language: English

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ALKALINE EARTH METAL COMPOUNDS
ANIMAL CELLS
ANIMAL TISSUES
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
BODY
CALCIUM COMPOUNDS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
CELL CULTURES
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENDOTHELIUM
ENZYME INHIBITORS
FLUORESCENCE
HEART
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
KINETICS
LUMINESCENCE
MAMMALS
MEMBRANE PROTEINS
MUSCLES
MYOCARDIUM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SYNTHESIS
TISSUES
VASOCONSTRICTORS
VERTEBRATES