title: Effects of acetaldehyde on action potentials and Ca2+ currents in single atrial myocytes from the bullfrog.
abstract: OBJECTIVE
  The purpose of the present study was to examine the effects of acetaldehyde on the contractile force and membrane potentials and currents in the bullfrog heart.
  
  
  METHODS
  Contractile force was recorded using right atrial tissues, and membrane potentials and currents were measured by using whole cell patch clamp methods in right atrial myocytes.
  
  
  RESULTS
  Acetaldehyde at 500 µmol/l and 1 mmol/l increased the contractile force significantly. Acetaldehyde at 300 and 500 µmol/l increased the overshoot and the plateau of electrically induced action potentials in a concentration-dependent and reversible manner, while the resting membrane potential did not change. The duration of the action potential (APD(90)) measured at the 90% repolarization level was shortened. The L-type Ca(2+) current (I(Ca)) increased significantly when 300 and 500 µmol/l were applied. The fast transient inward current, the inward rectifying potassium current and the outward delayed-rectifier potassium current were not changed following acetaldehyde application (500 µmol/l or 1 mmol/l).
  
  
  CONCLUSIONS
  These results suggest that acetaldehyde increased the I(Ca), thereby increased the contractile force, the overshoot and the plateau of action potentials. The shortening of APD(90) may be due to the acceleration of the current decay during the I(Ca) inactivation phase.
authors.affiliation: Department of Physical Education, National Dong Hwa University, Shoufeng, Taiwan, ROC.
authors.forename: Fu-Shih
authors.initials: FS
authors.lastname: Chen
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Satoh
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ide
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sugano
authors.forename: Minami
authors.initials: M
authors.lastname: Iimura
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Momose
authors.forename: Katsuharu
authors.initials: K
authors.lastname: Tsuchida
authors.forename: Megumi
authors.initials: M
authors.lastname: Tagami
mesh_terms: D000079:Acetaldehyde / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000187:drug effects; D006325:Heart Atria / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000502:physiology; D015221:Potassium Channels / Q000187:drug effects; D011892:Rana catesbeiana
chemical_list: D020746:Calcium Channels, L-Type; D015221:Potassium Channels; D000079:Acetaldehyde; D002118:Calcium