TY - JOUR
T1 - Ligand Binding Kinetics of Substance P and Neurokinin A Receptors Stably Expressed in Chinese Hamster Ovary Cells and Evidence for Differential Stimulation of Inositol 1,4,5‐Trisphosphate and Cyclic AMP Second Messenger Responses
AU - Takeda, Yasuo
AU - Blount, Paul
AU - Sachais, Bruce S.
AU - Hershey, Andrew D.
AU - Raddatz, Rita
AU - Krause, James E.
PY - 1992/8
Y1 - 1992/8
N2 - Abstract: Stably transfected Chinese hamster ovary cells expressing either the substance P receptor or neurokinin A receptor were constructed, isolated, and characterized. Equilibrium ligand binding studies performed on whole cells demonstrated that cell lines expressing either of these receptors contained a single class of high‐affinity binding sites with an apparent KD of 0.16 nM for the substance P receptor and an apparent KD of 2.1 nM for the neurokinin A receptor. The higher affinity of substance P for its receptor was accounted for by both a greater association rate constant and a lesser dissociation rate constant. The time course and extent of ligand‐stimulated inositol 1,4,5‐trisphosphate mass increases in both cell lines were similar and displayed rapid and transient kinetics. Ligand‐stimulated cyclic AMP accumulation was also apparent in the cell lines, although the time course and magnitude of the responses were substantially different, with the neurokinin A receptor mediating a greater and more prolonged response. These studies establish the presence of functional substance P receptors and neurokinin A receptors in the stably transfected cell lines and provide evidence for agonist‐dependent differential stimulation of second messenger responses.
AB - Abstract: Stably transfected Chinese hamster ovary cells expressing either the substance P receptor or neurokinin A receptor were constructed, isolated, and characterized. Equilibrium ligand binding studies performed on whole cells demonstrated that cell lines expressing either of these receptors contained a single class of high‐affinity binding sites with an apparent KD of 0.16 nM for the substance P receptor and an apparent KD of 2.1 nM for the neurokinin A receptor. The higher affinity of substance P for its receptor was accounted for by both a greater association rate constant and a lesser dissociation rate constant. The time course and extent of ligand‐stimulated inositol 1,4,5‐trisphosphate mass increases in both cell lines were similar and displayed rapid and transient kinetics. Ligand‐stimulated cyclic AMP accumulation was also apparent in the cell lines, although the time course and magnitude of the responses were substantially different, with the neurokinin A receptor mediating a greater and more prolonged response. These studies establish the presence of functional substance P receptors and neurokinin A receptors in the stably transfected cell lines and provide evidence for agonist‐dependent differential stimulation of second messenger responses.
KW - Chinese hamster ovary cells
KW - Cyclic AMP
KW - Differential stimulation
KW - Inositol 1,4,5‐trisphosphate
KW - Neurokinin A receptor
KW - Second messenger responses
KW - Substance P receptor
KW - Tachykinins
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U2 - 10.1111/j.1471-4159.1992.tb09430.x
DO - 10.1111/j.1471-4159.1992.tb09430.x
M3 - Article
C2 - 1321234
AN - SCOPUS:0026683453
SN - 0022-3042
VL - 59
SP - 740
EP - 745
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
IS - 2
ER -