Exercise-induced apoptosis of rat skeletal muscle and the effect of meloxicam

Abstract.

The aim of this study was to evaluate the effect of exercise on apoptosis in rat gastrocnemius and soleus muscle tissue and to determine the effect of meloxicam, a novel non-steroidal anti-inflammatory drug (NSAID), on the ratio of exercise-induced apoptosis. Forty male Wistar rats were used in the experiments. Spontaneous wheel-running was used as an exercise protocol. Rats were divided randomly into four groups. Group A (n=10) was the control group, in which rats did not perform any exercise. In group B (n=10), gastrocnemius and soleus muscles were biopsied immediately after exercise. The rats in group C (n=10) were placed back in their cages after exercise and allowed to rest for 48 h, after which the gastrocnemius and soleus muscles were biopsied. In group D (n=10), rats were given 11 mg meloxicam (Mobic, Boehringer Ingelheim) per kilogram body weight per day p.o. for 2 days, after which gastrocnemius and soleus muscles were biopsied 48 h after exercise. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP)-biotin nick end labelling (TUNEL) technique was used to detect DNA fragmentation in situ. TUNEL-positive nuclei were identified and counted. The apoptosis ratio in gastrocnemius muscle was 0.50×10^–3±0.96×10^–3 in group A, 5.42×10^–3±3.58×10^–3 in group B, 3.55×10^–3±3.23×10^–3 in Group C and 3.52×10^–3±1.00 in Group D; the ratios in soleus muscle were 0.98×10^–3±1.83×10^–3, 3.03×10^–3±2.78×10^–3, 4.48×10^–3±3.32×10^–3 and 2.91×10^–3±1.98×10^–3, respectively. The differences between the apoptosis ratios in group A and B, Group A and C, and Group A and D were statistically significant (P<0.05). There was no statistically significant difference between group C and D. In conclusion, exercise increased apoptosis in gastrocnemius and soleus muscle tissue, and the apoptosis ratios were not affected by meloxicam.