Acta Pharmacologica Sinica 2005 January; 26 (1): 113-116; doi: 10.1111/j.1745-7254.2005.00015.x

Acta Pharmacologica Sinica 2005 January; 26 (1): 113-116; doi: 10.1111/j.1745-7254.2005.00015.x

Original Article

Evaluation of drug-muscarinic receptor affinities using cell membrane chromatography and radioligand binding assay in guinea pig jejunum membrane

Bing-xiang YUAN¹, Jin HOU, Lang-chong HE², Guang-de YANG²

Department of Pharmacology; ¹Pharmacy College, Xi-an Jiaotong University, Xi-an 710061, China

Aim: 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.

Conclusion: The CMC method can be used to evaluate drug-receptor affinities for drug candidates.

Keywords: chromatography; cell membrane; muscarinic receptors; radioligand assay; jejunumchromatography; cell membrane; muscarinic receptors; radioligand assay; jejunum

¹ This work was supported by research grants from the Chang Gung Memorial Hospital (CMRPG- 83027, 83030, and 83033).

¹ Corresponding to Prof. Bing-xiang YUAN.
Phn 86-29-8265-5165.
E-mail ybx@mail.xjtu.edu.cn
Received 2004-02-03 Accepted 2004-06-22

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