title: Studies on the mechanism of positive inotropic effect of hymoquinolone.
abstract: Mechanism of positive inotropic action of hymoquinolone (7-hydroxy-8-methoxy-4(1H)-quinolone) (Q), a new compound isolated from Chinese Soft Sinularia polydactyla and Sinularia lettoclados, was studied using radioimmunoassay. Q caused positive inotropic action accompanied by elevated cAMP level in left and right atria of guinea pig at the concentration of 0.34 mM. The evidence that Q inhibited phosphodiesterase activity and did not affect adenylate cyclase activity led to the conclusion that Q may be an inhibitor of phosphodiesterase, thereby increasing cAMP level and producing positive inotropic actions.
authors.affiliation: Department of Biology, Zhongshan University, Guangzhou, China.
authors.forename: S B
authors.initials: SB
authors.lastname: Xu
authors.forename: L X
authors.initials: LX
authors.lastname: Yue
authors.forename: K H
authors.initials: KH
authors.lastname: Long
authors.forename: Y C
authors.initials: YC
authors.lastname: Lin
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D015363:Quinolones / Q000494:pharmacology*; D011863:Radioimmunoassay
chemical_list: D002316:Cardiotonic Agents; D007202:Indicators and Reagents; D015363:Quinolones; D010042:Ouabain; C078803:hymoquinolone; D000242:Cyclic AMP; D010727:Phosphoric Diester Hydrolases; D000262:Adenylyl Cyclases; D007545:Isoproterenol