Pharmacological characterization and autoradiographic localization of substance P receptors in guinea pig brain

Journal Article · Mon Sep 01 04:00:00 EDT 1986 · Peptides (Fayetteville, N.Y.); (United States)

DOI:https://doi.org/10.1016/0196-9781(86)90106-3· OSTI ID:6802683

Dam, T V; Quirion, R

(/sup 3/H)Substance P ((/sup 3/H)SP) was used to characterize substance P (SP) receptor binding sites in guinea pig brain using membrane preparations and in vitro receptor autoradiography. Curvilinear Scatchard analysis shows that (/sup 3/H)SP binds to a high affinity site (Kd = 0.5 nM) with a Bmax of 16.4 fmol/mg protein and a low affinity site (Kd = 29.6 nM) with a Bmax of 189.1 fmol/mg protein. Monovalent cations generally inhibit (/sup 3/H)SP binding while divalent cations substantially increased it. The ligand selectivity pattern is generally similar to the one observed in rat brain membrane preparation with SP being more potent than SP fragments and other tachykinins. However, the potency of various nucleotides is different with GMP-PNP greater than GDP greater than GTP. The autoradiographic distribution of (/sup 3/H)SP binding sites shows that high amounts of sites are present in the hippocampus, striatum, olfactory bulb, central nucleus of the amygdala, certain thalamic nuclei and superior colliculus. The cortex is moderately enriched in (/sup 3/H)SP binding sites while the substantia nigra contains only very low amounts of sites. Thus, the autoradiographic distribution of SP binding sites is fairly similar in both rat and guinea pig brain.

• Research Organization: Douglas Hospital Research Centre, Quebec
• OSTI ID: 6802683
• Journal Information: Peptides (Fayetteville, N.Y.); (United States), Journal Name: Peptides (Fayetteville, N.Y.); (United States) Vol. 5; ISSN PPTDD
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMALS
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL LOCALIZATION
BODY
BRAIN
CATIONS
CENTRAL NERVOUS SYSTEM
CHARGED PARTICLES
DISTRIBUTION
GUINEA PIGS
IONS
KINETICS
LABELLED COMPOUNDS
LIGANDS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
PROTEINS
REACTION KINETICS
RECEPTORS
RODENTS
TISSUE DISTRIBUTION
TRITIUM COMPOUNDS
VALENCE
VERTEBRATES