Differences in QNB binding between freshly isolated and cultured single cells prepared from longitudinal smooth muscle of guinea pig ileum

• Published in: Japanese Journal of Pharmacology 1989, Vol.49 (suppl), p.282-282
• Main Authors: Ohtsuka, Kazuko, Maeda, Takashi, Kamiya, Tomoko, Maruyama, Ikuo, Momose, Kazutaka
• Format: Article
• Language: English
• ISSN: 0021-5198; 1347-3506
• DOI: 10.1016/S0021-5198(19)56682-3

Binding of [3 H]QNB (quinuclidinyl benzilate) in freshly isolated smooth muscle cells and cultured cells from longitudinal smooth muscle of guinea pig ileum were investigated. Single cells prepared with a combination of purified collagenase and papain were used for the QNB-binding assay (Takayanagi et al., J. Pharm. Pharmacol., 38, 476, 1985). Single cells were cultured in Dulbecco's Modified Eagle's medium at 37°, overnight. By Scatchard analysis, freshly prepared cells had two types of affinity sites, while the cultured cells had one. By the addition of 5'-guanylyl-imidodiphosphate (GppNHp), the affinity sites for QNB were changed from two to one in freshly prepared single cells and from one to two in cultured cells. These results suggested that the receptor protein might be damaged during the isolation procedure.