O efeito do estrógeno nas reservas glicogênicas de musculoesqueléticos desnervados de ratas

Abstract

Objective: To evaluate the effects of estrogen on muscles in female rats subjected to hindlimb denervation. Methods: Female Wistar rats were divided into five groups (n= 6): control; denervated 7 days; denervated 15 days; denervated treated with estrogen (200μg/rat, subcutaneously, daily) for 7 days; and denervated treated with estrogen for 15 days. After the experimental periods, glycogen (GLY) evaluations were performed on the soleus (S), white gastrocnemius (WG) and red gastrocnemius (RG), and the soleus was weighed. The statistical analysis was performed using the normality test, ANOVA and Tukey test (p< 0.05). Results: The denervation caused a reduction (p< 0.05) in GLY over a 7-day period (S: 44%, WG: 32%; RG: 32%) and 15-day period (S: 62%, WG: 44%; RG: 53%), and also S weight reduction (7 days: 29.7%; 15 days: 36.6%). However, the estrogen treatment caused elevation (p< 0.05) of GLY under this condition, both over 7 days (S: 19%; WG: 60%; RG: 18%) and over 15 days (S: 52%; WG: 51%; RG: 11%), but it was not enough to minimize the muscle weight reduction. Conclusions: The treatment with low doses of estrogen minimized the metabolic alterations induced by denervation, but it was not effective in interfering in the weight loss of the soleus muscle. This suggests that the hormone acts by enabling chemical-metabolic protection that acts like the insulin route, but the effect is multifactorial and depends on the dose, manner and duration of the treatment, as well as the time since denervation.