Muscle Response to the Association of Statin and Physical Exercise in Rats

Abstract

SUMMARY:Physical exercise and statins, which are recommended for the treatment of dyslipidemia, are independently associated to the occurrence of muscle injury. The objective is analyze the effect of aerobic exercise associated to the use of simvastatin on the morphology of the gastrocnemius muscle. Thirty Wistar rats were divided into six groups, two of which received a standard diet (1 sedentary and 1 exercised) and four (1 sedentary with medication, 1 sedentary without medication, 1 exercised with medication, 1 exercised without medication) received a hypercholesterolemic diet (standard diet with the addition of cholesterol and coconut oil). Simvastatin (20 mg/Kg) was administered five days a week for eight weeks, together with aerobic training on a treadmill (9.75 m/min) for 60 minutes a day. The gastrocnemius muscle was removed, sliced, stained with Hematoxylin-Eosin and submitted to a histochemical reaction to determine mitochondrial activity. The data were analyzed using a paired t-test, analysis of variance and Scheffé's post hoc test (p<0.05). Greater histological alterations were found in the medicated and exercised animals, with a greater frequency of occurrence as well. The histochemical analysis revealed that the medicated groups had fibers with more intensive mitochondrial activity alongside fibers with an absence of reaction. The morphometric analysis revealed no significant differences between groups. It is suggested that simvastatin is a medication that leads to the occurrence of muscle injury and its administration in association with physical activity may exacerbate these injuries. This finding may be related to cellular respiration.

Effects of simvastatin associated with exercise on the mechanical resistance of muscle and bone in rats

“… 19 Rats in which simvastatin is used present morphological and structural changes that may be aggravated when the use of this drug is associated with exercise. 5 , 20 Bonfim et al 21 reported that the association of simvastatin with treadmill exercise led to an increase in the muscle injury in rats. In the present study, no statistically significant differences were observed in the mechanical properties of animals, regardless of the use of simvastatin.…”

Histological analysis of the association of low level laser therapy and platelet-rich plasma in regeneration of muscle injury in rats

“…Muscle injury promotes intense inflammatory infiltrate in the acute phase, 6 with necrotic fibers and the presence of rounded, angled, polymorphic and atrophic cells. 20 , 23 , 24 As time progresses the regeneration process becomes predominant and the presence of abnormal cells and inflammatory infiltrates decreases. New muscle fibers are generated as well as connective tissue deposition, which can lead to uncontrolled fibrosis scarring.…”

Efeito do exercício físico e estatinas na função muscular em animais com dislipidemia

“…In the present study, edema, splitting and cells of the conjunctive tissue with inflammatory infiltrate in 40 and 30% of the animals, respectively was identified in the groups submitted to physical exercise associated with commercial food (G5) and the hypercholesterolemic diet (G7). Bonfim et al 20 also identified muscular alterations in the gastrocnemius muscle, with special attention to inflammatory infiltrate in all animals treated with commercial food and physical exercise. Actually, physical exercise per se only leads to injuries in the skeletal musculature, which on its turn, cause adaptive process, altering both shape and structure of the muscle fibers, as well as promoting inflammatory response 14,18 .…”

“…In the group which performed the same treatment and practiced exercise, the mentioned muscle alterations occurred in addition to atrophic fibers and with longitudinal division process (splitting), in 90% of the animals. Bonfim et al 20 submitted Wistar rats to the treatment with simvastatin and physical exercise and also detected in the histological analysis in the muscle injuries of the gastrocnemius muscle including splitting (frequency of 40%), atrophic fibers (frequency of 60%) polymorphism of the muscle fibers and inflammatory infiltrate, both with frequency of 100%. In the sedentary group with use of simvastatin the same histological alterations have been observed, but with lower frequency.…”