Evaluation of efforts in untrained Wistar rats following exercise on forced running wheel at maximal lactate steady state

Abstract

[Purpose]We aimed to examine the effect of running speed on metabolic responses associated with maximal lactate steady state (MLSS) in rats during forced running wheel (FRW) exercise. [Methods]Forty male adult Wistar rats were divided into seven groups. The blood lactate threshold and peak running speed were determined for an incremental power test group. Five groups participated in constant power tests at intensities 10, 13, 14.5, 16, and 17.5 m/min to determine MLSS and a non-exercise group was chosen as the control. Animals were euthanized immediately after constant power tests and their corticosterone, non-esterified fatty acid (NEFA), blood glucose, and creatine kinase (CK) levels analyzed. The differences among groups were identified by one-way analysis of variance (p < 0.05). [Results]Blood lactate threshold corresponded a running intensity of 15 m/min, while MLSS was determined to be 16 m/min. Serum corticosterone concentrations were significantly higher in 14.5, 16, and 17.5 m/min groups (298.8±62, 338.3±65, and 354±26 nM, respectively) as compared to that in the control group (210.6±16 nM). Concentrations of NEFA observed in groups 13, 14.5, 16, and 17.5 m/min (662.8±24, 702.35±69, 718.4±34, and 752.8±77 μM, respectively) were significantly higher than those in 10 m/min and control groups (511.1±53 and 412.1±56 μM, respectively). The serum CK concentration recorded for group 17.5 m/min (372.4±56 U/L) was higher than those recorded for other groups. [Conclusion]The speed above 16 m/min on FRW resulted in increased physiological demands and muscle damage in untrained healthy Wistar rats.

Ultra-Endurance Associated With Moderate Exercise in Rats Induces Cerebellar Oxidative Stress and Impairs Reactive GFAP Isoform Profile

“…The serum CK concentrations here detected in the MV-ET and HV groups were higher than those observed after moderate-intensity protocols in animal models ( De Araujo et al, 2012 ) even when submitted to the eccentric contraction exercise by downhill running ( Isanejad et al, 2015 ) or even when performed at a high intensity ( Choi et al, 2013 ; Rezaei et al, 2017 ). Wistar rats, when subjected to progressively intense exercise, can reach anaerobic thresholds at velocities exceeding 15 m/min and a maximum CK concentration close to 350 U/L at 17.5 m/min ( Rezaei et al, 2017 ). In the MV-ET and HV groups, higher serum CK concentrations were detected under the aerobic threshold, at a velocity not exceeding 12 m/min and in the absence of increased levels of LDH in the serum.…”

Hypothalamic Crh/Avp, Plasmatic Glucose and Lactate Remain Unchanged During Habituation to Forced Exercise

“…The activation of the hypothalamic-pituitary-adrenal axis implies an ACTH release, which leads to a glucocorticoid effect that raises hepatic glycogenolysis, activates glycogen synthase and decreases the cellular glucose consumption. This process finally increases the plasmatic glucose levels (Stalmans and Laloux, 1979;Schneiter and Tappy, 1998;Rezaei et al, 2017). Acute stress also increases plasmatic epinephrine and norepinephrine involving the sympathetic-adrenal and catecholaminergic system, which can be related with a rise of lactate by the effects of glycogenolysis and glycolysis in the cellular cytosol (van Stegeren et al, 2010;Garcia-Alvarez et al, 2014;Godoy et al, 2018).…”

“…Plasmatic lactate and glucose have been proven to be robust biomarkers of stress response; which are boosted after running and reach higher values when the intensity of the exercise surpasses the lactate threshold (Raastad et al, 2000;Saito and Soya, 2004;Soya et al, 2007;Bórnez et al, 2009;Romero Peñuela et al, 2011;Garcia-Alvarez et al, 2014;Rezaei et al, 2017). Once the lactate threshold is reached during running in treadmill or in forced wheel, a quick gain of glucose, lactate and ACTH can be observed (Timofeeva et al, 2003;Soya et al, 2007;Rezaei et al, 2017). The activation of the hypothalamic-pituitary-adrenal axis implies an ACTH release, which leads to a glucocorticoid effect that raises hepatic glycogenolysis, activates glycogen synthase and decreases the cellular glucose consumption.…”

“…These changes promote energy utilization that readies the organism for the fight-or-flight response by increasing heart rate, blood pressure or plasmatic glucose and lactate concentrations (Tan et al, 1992;Moraska et al, 2000;Chennaoui et al, 2002;Andersen et al, 2004;Kawashima et al, 2004;Soya et al, 2007;Yanagita et al, 2007;Romero Peñuela et al, 2011;Chen et al, 2017;Godoy et al, 2018). Plasmatic glucose and lactate levels have been considered useful markers of stress response after acute exercise (Raastad et al, 2000;Saito and Soya, 2004;Soya et al, 2007;Bórnez et al, 2009;Romero Peñuela et al, 2011;Garcia-Alvarez et al, 2014;Rezaei et al, 2017). Fluctuations of these physiological responses depend on the different types and intensities of exercise.…”

Rehabilitation Effects of Fatigue-Controlled Treadmill Training After Stroke: A Rat Model Study

“…They were housed in a 12/12 h light/dark vivarium with ad libitum access to food and water except for experimental periods. All animals went through a 30 min treadmill running at the speed of 16 m/min per day for 3 consecutive days to get familiar with running on the treadmill (Rezaei et al, 2017). The length of the runway was 50 cm, and the treadmill controller would show the accumulative running duration (ZH-PT animal experiment treadmill, Anhui Zhenghua Biological Instrument, China).…”