Efeitos do exercício físico agudo na contratilidade intestinal em camundongos swiss

Abstract

Studies of the physiological repercussions promoted by physical exercise are frequently directed towards the cardiovascular, respiratory and muscular systems, and the repercussion of exercise in the gastrointestinal tract (GIT) is generally neglected. From this, we aimed to evaluate the effects of acute exercise on intestinal smooth muscle contractility in isolated ileum samples of swiss mice. To assess tissue responsiveness, the gut preparations were precontracted by Potassium chloride (KCl) (60 mM), washed and soon after starting a curve with cumulative concentrations of Acetilcoline (ACh), (10-9-10-2M). The contractile response in grams (g) of the small intestine of mice exposed to resistance training (T) was significantly higher (p <0.05, Student's T test) than the 10-4M sedentary control group (S) T = 1.186 ± 0.015 vs S = 0.901 ± 0.048), 10-3M (T = 1.261 ± 0.011 vs S = 0.938 ± 0.054) and 10-2M (T = 1.366 ± 0.016 vs S = 0.898 ± 0.067). When we compared the tension variation (Δg) promoted by the pharmacomechanical coupling stimulus ACh, we obtained a significant difference in the same concentrations previously demonstrated, 10-4M (T = 0.432 ± 0.021 vs S = 0.255 ± 0.033), 10-3M (T = 0.582 ± 0.031 vs S = 0.294 ± 0.031), and 10-2M (T = 0.714 ± 0.017 vs. S = 0.216 ± 0.037). As a percentage of the tension variation (%Δg) in relation to KCl, obtaining a significant difference in the same concentrations of ACh, 10-4M (T = 59.5 ± 3,295 vs S = 42,7 ± 2,345), 10-3M (T = 70.33 ± 2.266 vs S = 47.06 ± 4.218) and 10-2M (T = 83.78 ± 3.098 vs S = 52.52 ± 3.512). It was concluded that physical exercise demonstrated a significant difference in comparison to the contraction in ileum preparations of sedentary animals. Regarding the comparison with the variation of tension promoted by KCl, in percentage, there was also a significant difference between the groups, from this we observed that in the present study the acute exercise was shown to be a stimulator of the contractile response in the intestinal smooth muscle, corroborating the literary findings that demonstrate important intestinal alterations promoted by the exercise even in acute character.