caa a22 4500 469078995 CHVBK 20180323132944.0 cr unu---uuuuu 170328e19920101xx s 000 0 eng 10.1007/BF00175472 doi (NATIONALLICENCE)springer-10.1007/BF00175472 Motilin and erythromycin enhance the in vitro contractile activity of the sphincter of Oddi of the Australian Brush-tailed Possum [Elektronische Daten] [Robert Baker, Gino Saccone, David Costi, Anders Thune, James Toouli] Summary: Erythromycin has been shown to interact with gastrointestinal smooth muscle in a similar manner to motilin, and has been postulated as a motilin receptor agonist. We report that in isolated preparations from the biliary tract of thirty one Australian Brush-tailed Possums (Trichosurus vulpecula) erythromycin acts in a similar manner to motilin. In all muscle strips from the sphincter of Oddi, prepared in both the circular and longitudinal orientation, both synthetic porcine motilin (10−10 M − 10−6 M) and erythromycin (lactobionate) (10−8 M − 10−4 M) stimulated contractile activity in a concentration dependant manner, via a direct effect on the smooth muscle (the response was unaffected by tetrodotoxin, omega conotoxin GVIA or atropine). In strips prepared from the gallbladder neither agonist affected the contractile activity in 7 of 8 animals. Motilin was approximately 1000 fold more potent in stimulating contractile activity than erythromycin in both sphincter of Oddi circular strips [pD2 for peak response to motilin 8.67 (mean) ± 0.06 (SEM) compared with erythromycin 5.67 ± 0.09] and sphincter of Oddi longitudinal strips [pD2 for peak response to motilin 8.64 (mean) ± 0.28 (SEM) compared with erythromycin 5.45 ± 0.23]. The concentration response curves for motilin and erythromycin were similar and both agonists required the presence of extracellular calcium to elicit responses (responses were diminished by verapamil and abolished in calcium free Krebs solution). Our results support the hypothesis that erythromycin mimics the action of motilin in stimulating the sphincter of Oddi in vitro. Springer-Verlag, 1992 Biliary motility nationallicence Isolated smooth muscle nationallicence Motilin nationallicence Erythromycin nationallicence Baker Robert Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut Saccone Gino Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut Costi David Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut Thune Anders Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut Toouli James Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/1(1992-01-01), 71-77 0028-1298 345:1<71 1992 345 210 https://doi.org/10.1007/BF00175472 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00175472 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Baker Robert Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Saccone Gino Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Costi David Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Thune Anders Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Toouli James Department of Surgery, Flinders University of South Australia, Bedford Park, 5042, Adelaide, South Australia, Australia aut NATIONALLICENCE 773 0- Naunyn-Schmiedeberg's Archives of Pharmacology Springer-Verlag 345/1(1992-01-01), 71-77 0028-1298 345:1<71 1992 345 210 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer