Abstract The aim of the present study was to investigate the effects of β-hydroxy-β-methylbutyrate (HMB) supplementation in association with concurrent training on morphological soleus muscle of rats. Wistar male rats were divided randomly into four groups: Control (C), Supplemented (S), Training (T) and Training + Supplemented (TS). Groups S and TS received 76mg/kg/day of HMB and the training groups (T and TS) were inserted into concurrent training program 3 times/week for 8 weeks. HMB had positive effects either on body composition of the animals or in type II muscle fibers. The concurrent exercise training was able in reducing the total fat mass as well as in increasing the diameter of muscle fibers. Our findings shows that HMB had an anti-catabolic effect with reference to the parameters of volume, weight and morphology of the soleus muscle, and there was a positive interaction between HMB supplementation and concurrent exercise training.

The aim of this study was to analyze changes in the skeletal muscle tissue of rats after muscle stretch injury using fractal analysis. Nineteen rats were divided into three groups, Control (n= 5) (C), Lesion two days (n= 7) (L2), and Lesion seven days (n= 7) (L7). Histological slides of the gastrocnemius muscle of the animals were prepared and stained with Hematoxylin and eosin for analysis of the inflammatory process, and picrosirius for the demonstration of collagen. The stained slides were subsequently analyzed using Fractal Dimension (FD). The results showed high FD values of the inflammatory process in the experimental groups L2 and L7 in relation to C (p= 0.000). The analysis of collagen in the picrosirius stained slides showed high FD in the L2 group compared to the L7 (p= 0.0001), with no statistically significant difference among other groups. In summary, the present study demonstrated that fractal analysis was able to identify changes in the inflammatory process in injured skeletal muscle tissue.

El objetivo de la investigación fue observar las modificaciones en tejido muscular esquelético en ratas después de la lesión por estiramiento muscular con análisis fractal. En el estudio se incluyeron 19 ratas, divididas en tres grupos, Control (n= 5) (C), lesión dos días (n= 7) (L2) y lesión siete días (L7). Los cortes histológicos del músculo gastrocnemio fueron coloreados con hematoxilina-eosina para el análisis de la inflamación y picrosirius para la determinación del colágeno. Los cortes histológicos fueron posteriormente analizados por medio de dimensión fractal (FD). Los resultados mostraron valores elevados de FD en proceso inflamatorio en los grupos experimentales L2 y L7, en comparación con grupo C (p= 0,000). El análisis de colágeno mostró mayor FD en grupo L2 comparado con L7 (p= 0,0001), se observó diferencia estadísticamente significativa con los demás. En resumen, esta investigación ha demostrado que el análisis fractal fue capaz de identificar las alteraciones del proceso inflamatorio en tejido muscular esquelético después de la lesión.