Influence of nonsteroidal anti-inflammatory drug treatment duration and time of onset on recovery from exercise-induced muscle damage in rats.
OBJECTIVE
To determine if duration and time of onset of treatment with diclofenac sodium influence force recovery after exercise-induced muscle damage in rats.


METHODS
Randomized placebo-controlled trial.


METHODS
Animal laboratory.


METHODS
A total of 217 female adult Wistar rats.


METHODS
Rats were submitted to a protocol consisting of 450 eccentric contractions of the ankle dorsiflexors. Treatment by gavage with diclofenac sodium (1 mg/kg, twice daily) was started at different times pre- and postprotocol or for various treatment durations.


METHODS
In vitro contractile properties.


RESULTS
When treatment was initiated shortly postprotocol, force recovery was roughly proportional to treatment duration during the first 3 days but not at 7 and 28 days postprotocol. A 7-day treatment was no more effective than 1- or 2-day treatments when force was measured at 7 and 28 days; however, such prolonged treatment had no deleterious effect on muscle force at either time. A single-dose prophylactic treatment was as effective as a 2-day treatment initiated soon after the protocol when force was assessed 2 days postprotocol; on the other end, a treatment delayed for 3 days had no effect when force was measured at 7 days.


CONCLUSIONS
Treatment with diclofenac sodium extending past the acute inflammatory phase was no more effective than short and timely treatment in this model of skeletal muscle damage.
Lapointe
Benoît M
BM
CHUL Research Center, Laval University, Quebec City, QC, Canada.
Frémont
Pierre
P
Côté
Claude H
CH
D000208:Acute Disease; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000494:pharmacology; D004008:Diclofenac / Q000008:administration & dosage* / Q000494:pharmacology; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D005260:Female; D007249:Inflammation; D007537:Isometric Contraction / Q000187:drug effects; D009220:Myositis / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D010805:Physical Conditioning, Animal / Q000009:adverse effects*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function / Q000187:drug effects*; D013997:Time Factors; D016896:Treatment Outcome
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004008:Diclofenac