Whole-Body Vibration Promotes Beneficial Changes on the Anterior Tibial Muscle Histomorphometry of Hypothalamic Obese Rats

Abstract

Background. Due to the deleterious effects of obesity on muscle tissue and the search for tools to reverse these losses, it is important to understand the effect of physical exercises on the muscle structure of obese individuals. This study aimed to analyze the effect of wholebody vibration (WBV) on the histomorphological parameters of the anterior tibial muscle using the monosodium l-glutamate (MSG) obesity model. Methods. MSG-obese rats that were exposed to WBV on a vibrating platform with a frequency of 60 Hz, the amplitude of 2 mm, three times/week, 10 min/day, for eight weeks (from postnatal day (PN) 80 to PN136). The histomorphology of the anterior tibial muscle was evaluated. Results. When performing a WBV exercise, the animals showed altered structural responses in the MSG animals, such as reduced muscle mass, increased connective tissue, and nuclear activity. The WBV reduced the extracellular matrix and the nuclear activity in the MSG animals, showing efficiency in the protocol. Conclusions. Even with the aggressive character of the MSG model, the WBV exercise was able to induce repair to the muscle tissue of these animals, thus being a safe protocol for use in similar conditions.

Early and Sustained Inflammatory State Induces Muscle Changes and Establishes Obesogenic Characteristics in Wistar Rats Exposed to MSG-Induced Obesity Model

“…Similarly, in a swimming model, adiposity reduction and insulin secretion did not return to physiological patterns and changes in intestinal structure were still persistent [58]. In our research group, whole-body vibration training, despite promoting anti-obesogenic effects, was not able to completely repair the soleus muscles [29,59], extensor digitorum longus [30], tibialis anterior [21] and diaphragm [60] muscles. Furthermore, it did not restore the biochemical and structural parameters of the liver, adipose tissue and plasma to physiological levels [9].…”

“…The MSG-obesity induction causes cytotoxic injury in hypothalamic nuclei that induces significant changes in the development of animals, mainly due to cell loss in the GH-secreting hypothalamic nuclei [28], as well described in the literature [7] and previously identified in works by our research group [9,21,29,30]. The relationship between reduced body growth and reduced muscle growth has also been extensively explored [1,22,28], with a consensus in the literature that MSG cytotoxicity still results in a model of short stature due to hormonal insufficiency that leads to low growth [22,31].…”

“…The reduction in body growth of animals exposed to the MSG model has been evidenced by several authors [1,9,[21][22][23]. Depending on the concentration and frequency of injections, the condition can be identified immediately after the induction period and is also confirmed in adulthood [22,24].…”