( sup 125 I)-Bolton-Hunter scyliorhinin II: A novel, selective radioligand for the tachykinin NK3 receptor in rat brain

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

DOI:https://doi.org/10.1016/0196-9781(90)90200-O· OSTI ID:6324751

Mussap, C J; Burcher, E ^[1]

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1. Deakin Univ., Victoria (Australia)

The cyclic tachykinin scyliorhinin II (SCYII) has high affinity for the (neurokinin B (NKB)-preferring) NK3 receptor. SCYII was iodinated using (125I)-Bolton-Hunter reagent and the product BHSCYII purified using reverse phase HPLC. In rat brain membranes, binding of BHSCYII and of the relatively unselective radioligand (125I)-Bolton-Hunter eledoisin (BHELE) was saturable, reversible and to an NK3 site. In competition studies, the rank order of potency in inhibiting binding of BHSCYII and BHELE was: SCYII greater than or equal to (MePhe7)-NKB approximately senktide greater than NKB greater than or equal to kassinin greater than or equal to eledoisin greater than (Pro7)-NKB greater than neurokinin A greater than neuropeptide K greater than or equal to substance P greater than (Sar9, Met(O2)11)-substance P. In cold saturation experiments, binding of BHELE occurred to a single class of high affinity sites (KD, 18.6 +/- 0.91 nM). Binding of BHSCYII was of greater affinity than for BHELE and could be resolved into a high (KD, 1.33 +/- 0.98 nM; 27% of sites) and low affinity (KD, 9.84 +/- 2.75; 73% of sites) component. The total number of binding sites was similar for both radioligands (BHSCYII, 8.27 +/- 0.98; BHELE, 7.94 +/- 0.32 fmol/mg wet weight). In vitro autoradiography in slide-mounted sections of rat brain showed identical binding patterns for both radioligands (100 pM), with dense binding localized predominantly to the cortex, Ammon's horn field 1, premammillary nuclei and interpeduncular nucleus.

• OSTI ID: 6324751
• Journal Information: Peptides (Fayetteville, New York); (USA), Journal Name: Peptides (Fayetteville, New York); (USA) Vol. 11:4; ISSN 0196-9781; ISSN PPTDD
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ANIMALS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
CHEMICAL REACTIONS
CHROMATOGRAPHY
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
HALOGENATION
INTERMEDIATE MASS NUCLEI
IODINATION
IODINE 125
IODINE ISOTOPES
ISOTOPES
KINETICS
KININS
LIGANDS
LIQUID COLUMN CHROMATOGRAPHY
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
POLYPEPTIDES
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
REAGENTS
RECEPTORS
RODENTS
SEPARATION PROCESSES
VERTEBRATES