Interaction of a vasopressin antagonist with vasopressin receptors in the septum of the rat brain

Journal Article · Fri Jan 01 00:00:00 EST 1988 · Synapse; (United States)

DOI:https://doi.org/10.1002/syn.890020306· OSTI ID:6354119

Dorsa, D M; Brot, M D; Shewey, L M; Meyers, K M; Szot, P; Miller, M A

The ability of d(CH2)5-Tyr(Me)-arginine-8-vasopressin, an antagonist of peripheral pressoric (V1-type) vasopressin receptors, to label vasopressin binding sites in the septum of the rat brain was evaluated. Using crude membrane preparations from the septum, /sup 3/H-arginine-8-vasopressin (AVP) specifically labels a single class of binding sites with a Kd of 2.9 nM and maximum binding site concentration of 19.8 fmole/mg protein. /sup 3/H-Antag also labels a single class of membrane sites but with higher affinity (Kd = 0.47 nM) and lower capacity (10.1 fmole/mg protein) than /sup 3/H-AVP. The rank order of potency of various competitor peptides for /sup 3/H-AVP and /sup 3/H-Antag binding was similar. Oxytocin was 100-1,000 fold less potent than AVP in competing for binding with both ligands. /sup 3/H-AVP and /sup 3/H-Antag showed similar labeling patterns when incubated with septal tissue slices. Unlabeled Antag also effectively antagonized vasopressin-stimulated phosphatidylinositol hydrolysis in septal tissue slices.

• Research Organization: Veterans Administration Medical Center, Seattle, WA (USA)
• OSTI ID: 6354119
• Journal Information: Synapse; (United States), Vol. 2:3
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
RECEPTORS
LABELLING
VASOPRESSIN
AUTORADIOGRAPHY
BIOCHEMICAL REACTION KINETICS
BRAIN
CELL MEMBRANES
IN VITRO
RATS
TRITIUM COMPOUNDS
ANIMALS
BODY
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
HORMONES
KINETICS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PEPTIDE HORMONES
PITUITARY HORMONES
PROTEINS
REACTION KINETICS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques