Evaluation of drug-muscarinic receptor affinities using cell membrane chromatography and radioligand binding assay in guinea pig jejunum membrane.
OBJECTIVE
To study if cell membrane chromatography (CMC) could reflect drug-receptor interaction and evaluate the affinity and competitive binding to muscarinic acetylcholine receptor (mAChR).


METHODS
The cell membrane stationary phase (CMSP) was prepared by immobilizing guinea pig jejunum cell membrane on the surface of a silica carrier, and was used for the rapid on-line chromatographic evaluation of ligand binding affinities to mAChR. The affinity to mAChR was also evaluated from radioligand binding assays (RBA) using the same jejunum membrane preparation.


RESULTS
The capacity factor (k') profiles in guinea pig jejunum CMSP were: (-)QNB (15.4)>(+)QNB (11.5)>atropine (5.35)>pirenzepine (5.26)>4-DAMP (4.45)>AF-DX116 (4.18)>pilocarpine (3.93)>acetylcholine (1.31). These results compared with the affinity rank orders obtained from radioligand binding assays indicated that there was a positive correlation (r2= 0.8525, P<0.0001) between both data sets.


CONCLUSIONS
The CMC method can be used to evaluate drug-receptor affinities for drug candidates.
Yuan
Bing-xiang
BX
Department of Pharmacology Pharmacy College, Xi-an Jiaotong University, Xi-an 710061, China. ybx@mail.xjtu.edu.cn
Hou
Jin
J
He
Lang-chong
LC
Yang
Guang-de
GD
D000818:Animals; D001285:Atropine / Q000378:metabolism; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism*; D002846:Chromatography, Affinity / Q000379:methods*; D004347:Drug Interactions; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007583:Jejunum / Q000648:ultrastructure; D008297:Male; D010890:Pirenzepine / Q000378:metabolism; D011813:Quinuclidinyl Benzilate / Q000378:metabolism; D011869:Radioligand Assay; D011976:Receptors, Muscarinic / Q000378:metabolism*
D011976:Receptors, Muscarinic; D010890:Pirenzepine; D011813:Quinuclidinyl Benzilate; D001285:Atropine