Abstract
Radioligand binding experiments were performed with crude homogenates from normal human skin in order to investigate substance P receptor density. Binding of [3H]substance P ([3H]SP) reached equilibrium after 20 min and was saturable analysis of saturation curves gave a significantly better fit using two-site binding compared to the single-site model. Competition studies employing some selective agonists for NK1, NK2 and NK3 receptors have demonstrated that only the NK1 selective agonist, [Sar9, Met(O2)11]-SP, was a competitor for [3H]SP binding. In addition, the non-hydrolyzable guanosine 5'-0-(3-thiotriphosphate) altered the dissociation of SP from NK1 receptors by increasing the number of low-affinity sites. These data show that in the skin [3H]SP binds to a single population of substance P high-affinity sites, which represent NK1-type receptors.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Aged
-
Binding, Competitive / drug effects
-
Female
-
Guanosine 5'-O-(3-Thiotriphosphate) / pharmacology
-
Humans
-
Male
-
Middle Aged
-
Neurokinin A / analogs & derivatives
-
Neurokinin A / pharmacology
-
Neurokinin B / analogs & derivatives
-
Neurokinin B / pharmacology
-
Peptide Fragments / pharmacology
-
Radioligand Assay
-
Receptors, Neurokinin-1 / agonists
-
Receptors, Neurokinin-1 / metabolism
-
Receptors, Neurokinin-2 / agonists
-
Receptors, Neurokinin-3 / agonists
-
Skin / drug effects
-
Skin / metabolism*
-
Substance P / analogs & derivatives
-
Substance P / metabolism*
-
Substance P / pharmacology
-
Tritium
Substances
-
Peptide Fragments
-
Receptors, Neurokinin-1
-
Receptors, Neurokinin-2
-
Receptors, Neurokinin-3
-
neurokinin B, MePhe(7)-
-
Tritium
-
substance P, Sar(9)-Met(O2)(11)-
-
neurokinin A(4-10), Tyr(5)-Trp(6,8,9)-Lys(10)-
-
Substance P
-
Guanosine 5'-O-(3-Thiotriphosphate)
-
Neurokinin A
-
Neurokinin B