Intensity of swimming exercise influences tracheal reactivity in rats

Abstract

Studies that evaluate the mechanisms for increased airway responsiveness are very sparse, although there are reports of exercise-induced bronchospasm. Therefore, we have evaluated the tracheal reactivity and the rate of lipid peroxidation after different intensities of swimming exercise in rats. Thus, male Wistar rats (age 8 weeks; 250–300 g) underwent a forced swimming exercise for 1 h whilst carrying attached loads of 3, 4, 5, 6 and 8% of their body weight (groups G3, G4, G5, G6 and G8, respectively; n=5 each). Immediately after the test, the trachea of each rat was removed and suspended in an organ bath to evaluate contractile and relaxant responses. The rate of lipid peroxidation was estimated by measuring malondialdehyde levels. According to a one-way ANOVA, all trained groups showed a significant decrease in the relaxation induced by aminophylline (10−12–10−1 M) (pD2=3.1, 3.2, 3.3, 3.3 and 3.2, respectively for G3, G4, G5, G6 and G8) compared to the control group (pD2=4.6) and the Emax values of G5, G6, G8 groups were reduced by 94.2, 88.0 and 77.0%, respectively. Additionally, all trained groups showed a significant increase in contraction induced by carbachol (10−9–10−3 M) (pD2=6.0, 6.5, 6.5, 7.2 and 7.3, respectively for G3, G4, G5, G6 and G8) compared to the control group (pD2=5.7). Lipid peroxidation levels of G3, G4 and G5 were similar in both the trachea and lung, however G6 and G8 presented an increased peroxidation in the trachea. In conclusion, a single bout of swimming exercise acutely altered tracheal responsiveness in an intensity-related manner and the elevation in lipid peroxidation indicates a degree of oxidative stress involvement.

Supplementation With Spirulina platensis Improves Tracheal Reactivity in Wistar Rats by Modulating Inflammation and Oxidative Stress

“…Here, carbachol worked as an inducer of cumulative contraction curves in tracheal rings. The results obtained for the control group demonstrated pEC50 values similar to those verified in previous research by Brito et al (2015) and Denis et al (2001) . Added to this, Albuquerque et al ( Albuquerque et al, 2016 ) report that the use of carbachol for contractions induction in tracheal rings was widely verified and accepted to study the reactivity of the trachea as a mimic of cholinergic stimulation.…”

Modeling exercise using optogenetically contractible Drosophila larvae

“…The tracheal system in flies is analogous to the respiratory tract or lungs that includes trachea in vertebrates [ 73 , 74 ]. It has been shown how various intensities of swimming exercise contribute to lung development and tracheal reactivity in humans and rodents, respectively [ 75 , 76 ]. Thus, genes identified in this category may provide insights into the mechanisms of how trachea and the respiratory tract in general are affected by various exercise modalities in humans.…”

Lactate thresholds and role of nitric oxide in male rats performing a test with forced swimming to exhaustion

“…Prior to experiments, all animals were adapted to water, with a subsequent recovery for 14 days (Brito et al, 2015 ). Adaptation consisted of keeping animals in shallow water at a temperature of 31 ± 1°C for 30 min for 14 days.…”