Characterization of neuropeptide Y binding sites in rat cardiac ventricular membranes

Journal Article · Tue May 01 00:00:00 EDT 1990 · Peptides (Fayetteville, New York); (USA)

DOI:https://doi.org/10.1016/0196-9781(90)90057-C· OSTI ID:6532061

Balasubramaniam, A; Sheriff, S; Rigel, D F; Fischer, J E ^[1]

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1. Univ. of Cincinnati Medical Center, OH (USA)

Neuropeptide Y (NPY) binding sites in rat cardiac ventricular membranes have been characterized in detail. {sup 125}I-NPY bound to the membranes with high affinity. Binding was saturable, reversible and specific, and depended on time, pH and temperature. Analysis of the binding data obtained under optimal conditions, 2 hr, 18 degrees C and at pH 7.5, revealed the presence of low and high affinity binding sites. The high affinity binding sites had an apparent dissociation constant (Kd) of 0.38 nM and a binding capacity (Bmax) of 7.13 fmol/mg protein. The apparent Kd and Bmax for low affinity binding sites were 22.34 nM and 261.25 fmol/mg protein, respectively. Peptides unrelated to NPY did not compete with 125I-NPY for the binding sites even at 1 microM concentrations, whereas homologous peptides, peptide YY (PYY) and pancreatic polypeptide (PP), and NPY(13-36) inhibited {sup 125}I-NPY binding but with lower potency compared to NPY. {sup 125}I-NPY binding was sensitive to the nonhydrolyzable GTP analog, Gpp(NH)p, suggesting that the NPY receptor is coupled to the adenylate cyclase system. The ventricular membrane receptor characterized in this study may play an important role in mediating the physiological effects of NPY in the heart.

• OSTI ID: 6532061
• Journal Information: Peptides (Fayetteville, New York); (USA), Journal Name: Peptides (Fayetteville, New York); (USA) Vol. 11:3; ISSN 0196-9781; ISSN PPTDD
• Country of Publication: United States
• Language: English

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550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMALS
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL COMPOSITION
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVES
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RECEPTORS
RODENTS
TEMPERATURE DEPENDENCE
TIME DEPENDENCE
TRACER TECHNIQUES
VERTEBRATES