title: Effects of ursolic acid on contractile activity of gastric smooth muscles.
abstract: Ursolic acid (UA) in concentrations of l x 10(7) mol/L - 5 x 10(5) mol/L induced relaxation in gastric smooth muscle (SM) tissues, in a concentration-dependent manner. The relaxation did not change membrane potential and slow wave contraction patterns. A significant decrease in amplitude and frequency of spike- potentials was observed. UA-induced reactivity was removed when SM preparations were treated with nifedipine (1 x 10(6) mol/L). Ca2+-induced contractions of the depolarized SM preparations (42 mmol/L K+; Ca2+-free Krebs solution) were substantially reduced in the presence of UA. It was determined that, in certain concentrations, UA influenced L - type Ca2+ channels, and reduced the Ca2+ influx.
authors.forename: Natalia
authors.initials: N
authors.lastname: Prissadova
authors.forename: Petko
authors.initials: P
authors.lastname: Bozov
authors.forename: Kiril
authors.initials: K
authors.lastname: Marinkov
authors.forename: Hristo
authors.initials: H
authors.lastname: Badakov
authors.forename: Atanas
authors.initials: A
authors.lastname: Kristev
mesh_terms: D000818:Animals; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013270:Stomach; D014315:Triterpenes / Q000737:chemistry / Q000494:pharmacology*; D000097245:Ursolic Acid
chemical_list: D014315:Triterpenes; D000097245:Ursolic Acid