title: Effect of propafenone on the contractile activity of Latissimus dorsi muscle isolated in an organ chamber: experimental study in rats.
abstract: OBJECTIVE
  To study the effect of propafenone on the contractile function of latissimus dorsi muscle isolated from rats in an organ chamber.
  
  
  METHODS
  We studied 20 latissimus dorsi muscles of Wistar rats and divided them into 2 groups: group I (n=10), or control group - we studied the feasibility of muscle contractility; group II (n=10), in which the contralateral muscles were grouped - we analyzed the effect of propafenone on muscle contractility. After building a muscle ring, 8 periods of sequential 2-minute baths were performed, with intervals of preprogrammed electrical stimulation using a pacemaker of 50 stimuli/min. In group II, propafenone, at the concentration of 9.8 microgram/mL, was added to the bath in period 2 and withdrawn in period 4.
  
  
  RESULTS
  In group I, no significant depression in muscle contraction occurred up to period 5 (p>0.05). In group II, a significant depression occurred in all periods, except between the last 2 periods (p<0.05). Comparing groups I and II only in period 1, which was a standard period for both groups, we found no significant difference (p>0.05).
  
  
  CONCLUSIONS
  Propafenone had a depressing effect on the contractile function of latissimus dorsi muscle isolated from rats and studied in an organ chamber.
authors.affiliation: Fundação Cardiovascular São Francisco de Assis.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Simões
authors.forename: Eduardo Luis Guimarães
authors.initials: EL
authors.lastname: Machado
authors.forename: Odilon Gariglio de Alvarenga
authors.initials: OG
authors.lastname: Freitas
authors.forename: Maria da Consolação Vieira
authors.initials: Mda C
authors.lastname: Moreira
authors.forename: Otoni Moreira
authors.initials: OM
authors.lastname: Gomes
mesh_terms: D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D003864:Depression, Chemical; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects*; D011405:Propafenone / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000889:Anti-Arrhythmia Agents; D011405:Propafenone