Characterization of the substance P receptor on the rat submaxillary gland

Thesis/Dissertation · Tue Jan 01 00:00:00 EST 1985

OSTI ID:5151408

Bahouth, S W

Substance P (SP) is an undecapeptide widely distributed in both the central and peripheral nervous systems. Its actions include vasodilation, intestinal contraction, salivation and probably nocioception, effects which are thought to be mediated by receptors. To characterize SP receptors, the binding of (/sup 3/H)SP and (/sup 3/H)physalaemin to rat submaxillary gland membranes and the effects of monovalent cations under conditions in which the peptides are protected from degradation and nonspecific adsorption to the filter were studied. In low ionic strength media (0.3 M sucrose) (/sup 3/H)SP binds to two sites, a high affinity one with an affinity (K/sub D/) = 0.14 nM and a receptor density (B/sub max/) = 370 fmole/mg, and a low affinity-high capacity site with a K/sub D/ = 1400 nM and B/sub max/ = 24,000 fmole/mg. Under these conditions physalaemin, which is about twice as potent as SP as a sialogogue, had one hundredth the potency of SP in competing with (/sup 3/H)SP, with an IC/sub 50/ = 150 nM. The increase in the ionic strength of the binding medium had a profound effect on the binding of (/sup 3/H)SP. The addition of monovalent cations reduced the non specific binding by 90%, abolished the low affinity-high capacity site and decreased the K/sub D/ of (/sup 3/H)SP.

• Research Organization: New York Univ., NY (USA)
• OSTI ID: 5151408
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PEPTIDES
CHEMICAL BONDS
RECEPTORS
AFFINITY
CATIONS
CELL MEMBRANES
CHEMICAL COMPOSITION
CULTURE MEDIA
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VALENCE
ANIMALS
CELL CONSTITUENTS
CHARGED PARTICLES
IONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MEMBRANES
ORGANIC COMPOUNDS
PROTEINS
RODENTS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques