title: The flavonoid chrysin, an endocrine disrupter, relaxes cholecystokinin- and KCl-induced tension in male guinea pig gallbladder strips through multiple signaling pathways.
abstract: The bioflavonoids have effects on vascular smooth muscle and gastrointestinal smooth muscle. The flavone and phytoestrogen, chrysin, has been shown to have a vasorelaxant effect on resistance blood vessels. This effect was mediated by nitric oxide (NO). Chrysin inhibited aromatase/estrogen biosynthesis in postmenopausal women. The purpose of this study was to determine if chrysin had an effect on cholecystokinin- or KCl-induced tension in male guinea pig gallbladder strips. In addition, the second messenger(s) system(s) that mediated the effect were to be determined. A pharmacologic approach was used. Male guinea pig gallbladder strips were placed in in vitro chambers filled with Krebs solution, maintained at 37 °C, and gassed with 95% O2-5% CO2. Changes in tension were recorded using a polygraph. It was shown that the PKA/cAMP second messenger system mediated part of the observed chrysin-induced relaxation of cholecystokinin-induced tension, the PKC system also mediated part of the relaxation, and the inhibition of both extracellular Ca(2+) entry and intracellular Ca(2+) release also mediated the chrysin-induced relaxation. This is the first report of chrysin having an effect on gallbladder smooth muscle contraction.
authors.affiliation: Department of Dentistry, University of Alberta, Edmonton T6G 2N8, Canada; University of Alberta, Department of Physiology, 7-55 Medical Sciences Building, Edmonton T6G 2H7, Alberta, Canada. Electronic address: lkline@ualberta.ca.
authors.forename: Loren W
authors.initials: LW
authors.lastname: Kline
authors.affiliation: University of Alberta, Department of Physiology, 7-55 Medical Sciences Building, Edmonton T6G 2H7, Alberta, Canada. Electronic address: ed.karpinski@ualberta.ca.
authors.forename: Edward
authors.initials: E
authors.lastname: Karpinski
mesh_terms: D000818:Animals; D053119:Benzophenanthridines / Q000494:pharmacology; D001896:Boron Compounds / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002756:Cholagogues and Choleretics / Q000494:pharmacology; D002766:Cholecystokinin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology*; D005704:Gallbladder / Q000502:physiology*; D006168:Guinea Pigs; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects* / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D011189:Potassium Chloride / Q000494:pharmacology*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology
chemical_list: D053119:Benzophenanthridines; D001896:Boron Compounds; D002756:Cholagogues and Choleretics; D052244:Endocrine Disruptors; D005419:Flavonoids; C043561:chrysin; D011189:Potassium Chloride; D015544:Inositol 1,4,5-Trisphosphate; D002766:Cholecystokinin; C016299:chelerythrine; C109986:2-aminoethoxydiphenyl borate; D011493:Protein Kinase C; D002118:Calcium
keywords: Calcium; Chrysin; Gallbladder; Phytoestrogen; Relaxation; Smooth muscle