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Identification of muscarinic receptor subtypes of cultured smooth muscle cells and tissue of human bladder body
Author(s) -
Kiwamoto Hiro,
Ma FuHai,
Higashira Hanae,
Park YungChol,
Kurita Takashi
Publication year - 2001
Publication title -
international journal of urology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 67
eISSN - 1442-2042
pISSN - 0919-8172
DOI - 10.1046/j.1442-2042.2001.00370.x
Subject(s) - muscarinic acetylcholine receptor , pirenzepine , muscarinic acetylcholine receptor m3 , receptor , muscarinic acetylcholine receptor m2 , endocrinology , methoctramine , detrusor muscle , medicine , cell culture , biology , microbiology and biotechnology , smooth muscle , genetics
Background: Muscarinic receptor subtypes of cultured smooth muscle cells from the human bladder body were investigated by the receptor binding assay method. The result was compared with that obtained from the human bladder body tissue to confirm whether the receptor subtypes of the cells are not changed after several passages of cell culture. Methods: Inhibitory effects of various muscarinic antagonists on the binding of [ 3 H]‐ N ‐methylscopolamine ([ 3 H]‐NMS) to membrane preparations obtained from cultured smooth muscle cells from the fourth subculture of the human bladder body were compared with those prepared from the human bladder body tissue and cells expressing human muscarinic receptor subtypes. Results: Binding‐inhibition constants (p K i ) for atropine, pirenzepine, methoctramine, 4‐diphenylacetoxy‐ N ‐methylpiperidine methiodide (4‐DAMP), oxybutynin and propiverine obtained from membrane preparations of cultured smooth muscle cells were 8.91, 6.35, 8.24, 8.53, 7.29 and 5.61, respectively. p K i values of these muscarinic receptor antagonists against the membrane preparation of human bladder body tissue were 9.08, 6.66, 8.05, 8.79, 7.53 and 6.04, respectively. p K i values of cultured smooth muscle cells and tissue from human bladder body were correlated closely with those of insect cells expressing the cloned human M 2 receptor subtype. Conclusion: The binding affinities for various muscarinic receptor antagonists of cultured human smooth muscle cells were maintained through the fourth subculture and it was suggested that the M 2 receptor subtype is predominantly expressed in cultured smooth muscle cells of human bladder body as well as in tissue of the human bladder body.