Substance P receptors in rat spleen: characterization and autoradiographic
distribution
CJ Wiedermann, K Sertl and CB Pert
The interaction of substance P with intact lymphatic tissue was quantified
and autoradiographically visualized, using slide-mounted tissue sections of
rat spleen. Radiolabeled substance P binds rapidly to an apparently single
class of noninteracting high affinity sites (Kd = 2.4 nmol/L; Bmax = 9.4
fmol/mg protein). The ligand selectivity pattern suggests that substance P
binding sites are similar to substance P receptors found in other tissues,
including the brain, T lymphocytes, and macrophages. Substance P receptors
are highly concentrated in the antigen-trapping spleen marginal zone, with
low densities being found in the red pulp. No specific binding of
radiolabel to T cell-dependent immunologic domains of the spleen is seen.
The distribution of substance P receptors suggests that substance P is
probably involved in the control of sensory functions of the immune system.
Volume 68,
Issue 6,
pp. 1398-1401,
12/01/1986
Copyright © 1986 by The American Society of Hematology
