Binding, internalization, and degradation of atrial natriuretic peptide in cultured vascular smooth muscle cells of rat
Binding, internalization, and degradation of /sup 125/I-labeled-rat atrial natriuretic peptide (rANP) were studied in cultured rat aortic vascular smooth muscle cells (VSMC). At 37 degrees C, /sup 125/I-labeled-rANP rapidly bound to VSMCs, but the cell-bound radioactivity rapidly decreased upon subsequent incubation, while the binding was slow at 4 degrees C, reaching to an apparent equilibrium after 6 hrs. The cell-bound /sup 125/I-labeled-rANP at 37 degrees C is rapidly dissociated from VSMC (t 1/2: approximately 40 min) with the appearance of degradaded product(s) of radioligand in the medium, whereas the degradation was minimal at 4 degrees C. This degradative process was blocked by inhibitors of metabolic energy production (azide, dinitrophenol), inhibitors of lysosomal cathepsins (leupeptin, pepstatin), and lysosomotropic agents (NH/sub 4/Cl, chloroquine, lidocaine, methylamine, dansylcadaverine), but not by inhibitors of serine or thiol proteases. /sup 125/I-labeled-rANP initially bound to the cell-surface was rapidly internalized, and delivered to lysosomal structures, which was confirmed by autoradiographic studies. These data indicate that rANP, after binding to the cell-surface receptors, is rapidly internalized into the cells through receptor-mediated endocytosis, and subsequently degradaded by lysosomal hydrolases.
- OSTI ID:
- 5809729
- Journal Information:
- Biochem. Biophys. Res. Commun.; (United States), Journal Name: Biochem. Biophys. Res. Commun.; (United States) Vol. 3; ISSN BBRCA
- Country of Publication:
- United States
- Language:
- English
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560301 -- Chemicals Metabolism & Toxicology-- Cells-- (-1987)
59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINES
AMMONIUM CHLORIDES
AMMONIUM COMPOUNDS
AMMONIUM HALIDES
ANIMALS
AROMATICS
AUTORADIOGRAPHY
AZIDES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CELL CULTURES
CHLORIDES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
DINITROPHENOL
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
HALIDES
HALOGEN COMPOUNDS
HYDROLASES
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGANDS
LYSOSOMES
MAMMALS
METABOLISM
METHYLAMINE
MUSCLES
NITRO COMPOUNDS
NITROGEN COMPOUNDS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
PEPTIDES
PHENOLS
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RODENTS
TRACER TECHNIQUES
VERTEBRATES