Strenuous swimming raises blood non-enzymatic antioxidant capacity in rats.

G Godoy,C.C Iwanaga,P.B Travassos,A.B Sá-Nakanishi,R.B Bazotte,R Curi,M.M Antunes,J.F Comar

doi:10.1590/1414-431x2022e11891

Abstract

The non-enzymatic antioxidant system protects blood components from oxidative damage and/or injury. Herein, plasma non-enzymatic antioxidant capacity after acute strenuous swimming exercise (Exe) and exercise until exhaustion (Exh) was measured in rats. The experiments were carried out in never exposed (Nex) and pre-exposed (Pex) groups. The Nex group did not undergo any previous training before the acute strenuous swimming test and the Pex group was submitted to daily swimming for 10 min in the first week and 15 min per day in the second week before testing. Plasma glucose, lactate, and pyruvate were measured and plasma total protein sulfhydryl groups (thiol), trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), and total radical-trapping antioxidant parameter (TRAP) levels were evaluated. There were marked increases in plasma lactate concentrations (Nex-Control 1.31±0.20 vs NexExe 4.16±0.39 vs NexExh 7.19±0.67) and in thiol (Nex-Control 271.9±5.6 vs NexExh 314.7±5.7), TEAC (Nex-Control 786.4±60.2 vs NexExh 1027.7±58.2), FRAP (Nex-Control 309.2±17.7 vs NexExh 413.4±24.3), and TRAP (Nex-Control 0.50±0.15 vs NexExh 2.6±0.32) levels after acute swimming and/or exhaustion. Also, there were increased plasma lactate concentrations (Pex-Control 1.39±0.15 vs PexExe 5.22±0.91 vs PexExh 10.07±0.49), thiol (Pex-Control 252.9±8.2 vs PexExh 284.6±6.7), FRAP (Pex-Control 296.5±15.4 vs PexExh 445.7±45.6), and TRAP (Pex-Control 1.8±0.1 vs PexExh 4.6±0.2) levels after acute swimming and/or exhaustion. Lactate showed the highest percent of elevation in the Nex and Pex groups. In conclusion, plasma lactate may contribute to plasma antioxidant defenses, and the TRAP assay is the most sensitive assay for assessing plasma non-antioxidant capacity after strenuous exercise.

Highlights

Cells have evolved a sophisticated enzymatic antioxidant system that includes enzymes such as glutathione peroxidase, glutathione reductase, superoxide dismutase, and catalase that scavenge and prevent reactive oxygen species (ROS) and reactive nitrogen species (RNS) accumulation [1]
The swimming sessions for the never exposed (Nex) and Pex groups were performed on different days
The histograms demonstrate that the trapping antioxidant parameter (TRAP) and lactate levels were elevated in the Nex and Pex exercise and exhaustion groups compared with the Nex-Control and Pex-Control groups, respectively

Summary

Introduction

Cells have evolved a sophisticated enzymatic antioxidant system that includes enzymes such as glutathione peroxidase, glutathione reductase, superoxide dismutase, and catalase that scavenge and prevent reactive oxygen species (ROS) and reactive nitrogen species (RNS) accumulation [1]. Plasma has been reported to have lower antioxidant enzyme activities than the intracellular environment [2]. This observation is due to the fact that plasma is continuously exposed to ROS [3] and contains nonenzymatic antioxidant substances, such as albumin, ascorbic acid, a-tocopherol, bilirubin, creatinine, and uric acid. This non-enzymatic antioxidant system protects blood components from oxidative damage and/or injury [4–7]. Intense and exhaustive exercise increases oxygen consumption and demand and stimulates oxidative phosphorylation and ROS generation [13,14], thereby inducing oxidative stress. Oxidant-induced (i.e., oxidative) damage has been linked to the onset and progression of diabetes, cardiovascular diseases, arthritis, cancer, and other diseases and disorders [4–6]

Methods

Results

Conclusion