caa a22 4500 469078715 CHVBK 20180323132943.0 cr unu---uuuuu 170328e19920801xx s 000 0 eng 10.1007/BF00165295 doi (NATIONALLICENCE)springer-10.1007/BF00165295 Characterization of the interaction of the cervane alkaloid, imperialine, at muscarinic receptors in vitro [Elektronische Daten] [R. Eglen, G. Harris, H. Cox, A. Sullivan, E. Stefanich, R. Whiting] Summary: The action of the cervane alkaloid, imperialine, has been assessed at M1, M2 and M3 receptors in functional assays and at M1, M2, M3 and putative M4 sites in binding studies. In functional studies, imperialine acted as a selective surmountable antagonist at M2 receptors in guinea-pig isolated atria and uterus (−log KB = 7.7 and 7.4, respectively), in comparison to M1, receptors in canine isolated saphenous vein (−log KB = 6.9) or M3 receptors in a range of guinea-pig isolated smooth muscles including ileum, trachea, fundus, seminal vesicle or oesophagus (−log KB = 6.6-6.8). In rat aorta, the −log KB value at the M3 receptor (5.9) was slightly, but significantly, lower. In competition radioligand binding studies, imperialine was also selective toward to M2 sites in rat myocardium (−log Ki = 7.2) with respect to M1 and M3 sites (rat cerebral cortex, rat submaxillary gland; −log Ki = 6.1 and 5.7, respectively). However, it did not significantly discriminate between rat cardiac M2 sites and putative M4 sites in rabbit lung (−log Ki = 6.9). Imperialine resembles the alkaloid himbacine in terms of its pharmacological profile at muscarinic receptor subtypes in that it acts as an M2 selective antagonist with respect to M1 or M3 sites. It may also provide a second, commercially available, antagonist with which to discriminate between M1 and M4 receptors. Springer-Verlag, 1992 Imperialine nationallicence Muscarinic receptor subtypes nationallicence Cervane alkaloids nationallicence Eglen R. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut Harris G. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut Cox H. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut Sullivan A. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut Stefanich E. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut Whiting R. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/2(1992-08-01), 144-151 0028-1298 346:2<144 1992 346 210 https://doi.org/10.1007/BF00165295 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00165295 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Eglen R. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut NATIONALLICENCE 700 1- Harris G. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut NATIONALLICENCE 700 1- Cox H. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut NATIONALLICENCE 700 1- Sullivan A. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut NATIONALLICENCE 700 1- Stefanich E. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut NATIONALLICENCE 700 1- Whiting R. Institute of Pharmacology, Syntex Research, 3401 Hillview Ave, 94304, Palo Alto, CA, USA aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 346/2(1992-08-01), 144-151 0028-1298 346:2<144 1992 346 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer