Effect of propafenone on the contractile activity of Latissimus dorsi muscle isolated in an organ chamber: experimental study in rats.
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 In group II, propafenone, at the concentration of 9.8 microgram/mL, was added to the bath in period 2 and withdrawn in period 4.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.
Simões
Ricardo
R
Fundação Cardiovascular São Francisco de Assis.
Machado
Eduardo Luis Guimarães
EL
Freitas
Odilon Gariglio de Alvarenga
OG
Moreira
Maria da Consolação Vieira
Mda C
Gomes
Otoni Moreira
OM
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
D000889:Anti-Arrhythmia Agents; D011405:Propafenone