title: Effects of nanomolar concentration dihydroouabain on calcium current and intracellular calcium in guinea pig ventricular myocytes.
abstract: The effects of nanomolar concentration of dihydroouabain (DHO) on L-type calcium current (ICa-L), TTX-sensitive calcium current (ICa(TTX)), and intracellular calcium concentration ([Ca2+]i) were investigated in guinea pig ventricular myocytes. The whole-cell patch-clamp technique was used to record ICa-L and ICa(TTX); [Ca2+]i was detected and recorded with the confocal microscopy. The nanomolar concentration of DHO increased the ICa-L, ICa(TTX), and [Ca2+]i, which could be partially inhibited by nisoldipine or TTX, but still appeared in the absence of extracellular K+ and Na+. These data suggest that DHO could increase [Ca2+]i in non-beating myocytes via stimulating the ICa-L and ICa(TTX), or perhaps triggering directly a release of intracellular calcium.
authors.affiliation: Department of Pharmacology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang, People's Republic of China.
authors.forename: Jingxiang
authors.initials: J
authors.lastname: Yin
authors.forename: Yongli
authors.initials: Y
authors.lastname: Wang
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Zhonglin
authors.initials: Z
authors.lastname: Shang
authors.forename: Suwen
authors.initials: S
authors.lastname: Su
authors.forename: Yanping
authors.initials: Y
authors.lastname: Cheng
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Xu
mesh_terms: D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020746:Calcium Channels, L-Type / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D015737:Nisoldipine / Q000494:pharmacology; D010042:Ouabain / Q000031:analogs & derivatives* / Q000494:pharmacology*; D018408:Patch-Clamp Techniques; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D002614:Chelating Agents; C000977:dihydroouabain; D013779:Tetrodotoxin; D015737:Nisoldipine; D004533:Egtazic Acid; D010042:Ouabain; D002118:Calcium