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Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats.

Scariot PP, Manchado-Gobatto Fde B, Torsoni AS, Dos Reis IG, Beck WR, Gobatto CA - Front Physiol (2016)

Bottom Line: We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT).In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties.This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT).

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Applied Sport Physiology, School of Applied Sciences, University of Campinas Limeira, Brazil.

ABSTRACT
Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home cages. This new finding is worth for scientists who work with animal models to study the protective effects of exercise.

No MeSH data available.


Related in: MedlinePlus

Gravimetric apparatus for measuring spontaneous physical activity of rats.
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Figure 1: Gravimetric apparatus for measuring spontaneous physical activity of rats.

Mentions: SPA of rats was measured using a gravimetric method adapted from Biesiadecki et al. (1999). As illustrated in Figure 1, animal's cages was placed on two iron platforms (47 × 40 cm) where was fixed between them a high sensitive load cell (primary sensor, PLA30Kgf®, Lider Balanças™). The output from the load cell was fed into a signal amplifier (MKTC5-10®, MK control and instrumentation™) and then to an analogic to digital board converter (USB-6008® signal-conditioning module) in a computer where it was collected at a frequency of 30 Hz using software developed from the LabView package (Signal Express® 2009, National Instruments™). The signal acquisition system was calibrated by applying known mass. Regression equations (R2 = 0.99) were then computed enabling conversions of milivolts (mv) signals to kilograms (kg) units. Biesiadecki et al. (1999) and other authors (Chausse et al., 2014; Moes and Holden, 2014; Beck et al., 2016) have shown the efficacy of gravimetric principle. Our apparatus was designed to be operated without human presence. Because it was not necessary to remove the rats from their own keeping cage in the biotery, it was possible to measure their natural SPA. This technique can provide accurate information about the animal's behavior.


Continuous Aerobic Training in Individualized Intensity Avoids Spontaneous Physical Activity Decline and Improves MCT1 Expression in Oxidative Muscle of Swimming Rats.

Scariot PP, Manchado-Gobatto Fde B, Torsoni AS, Dos Reis IG, Beck WR, Gobatto CA - Front Physiol (2016)

Gravimetric apparatus for measuring spontaneous physical activity of rats.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4834519&req=5

Figure 1: Gravimetric apparatus for measuring spontaneous physical activity of rats.
Mentions: SPA of rats was measured using a gravimetric method adapted from Biesiadecki et al. (1999). As illustrated in Figure 1, animal's cages was placed on two iron platforms (47 × 40 cm) where was fixed between them a high sensitive load cell (primary sensor, PLA30Kgf®, Lider Balanças™). The output from the load cell was fed into a signal amplifier (MKTC5-10®, MK control and instrumentation™) and then to an analogic to digital board converter (USB-6008® signal-conditioning module) in a computer where it was collected at a frequency of 30 Hz using software developed from the LabView package (Signal Express® 2009, National Instruments™). The signal acquisition system was calibrated by applying known mass. Regression equations (R2 = 0.99) were then computed enabling conversions of milivolts (mv) signals to kilograms (kg) units. Biesiadecki et al. (1999) and other authors (Chausse et al., 2014; Moes and Holden, 2014; Beck et al., 2016) have shown the efficacy of gravimetric principle. Our apparatus was designed to be operated without human presence. Because it was not necessary to remove the rats from their own keeping cage in the biotery, it was possible to measure their natural SPA. This technique can provide accurate information about the animal's behavior.

Bottom Line: We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT).In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties.This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT).

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Applied Sport Physiology, School of Applied Sciences, University of Campinas Limeira, Brazil.

ABSTRACT
Although aerobic training has been shown to affect the lactate transport of skeletal muscle, there is no information concerning the effect of continuous aerobic training on spontaneous physical activity (SPA). Because every movement in daily life (i.e., SPA) is generated by skeletal muscle, we think that it is possible that an improvement of SPA could affect the physiological properties of muscle with regard to lactate transport. The aim of this study was to evaluate the effect of 12 weeks of continuous aerobic training in individualized intensity on SPA of rats and their gene expressions of monocarboxylate transporters (MCT) 1 and 4 in soleus (oxidative) and white gastrocnemius (glycolytic) muscles. We also analyzed the effect of continuous aerobic training on aerobic and anaerobic parameters using the lactate minimum test (LMT). Sixty-day-old rats were randomly divided into three groups: a baseline group in which rats were evaluated prior to initiation of the study; a control group (Co) in which rats were kept without any treatment during 12 weeks; and a chronic exercise group (Tr) in which rats swam for 40 min/day, 5 days/week at 80% of anaerobic threshold during 12 weeks. After the experimental period, SPA of rats was measured using a gravimetric method. Rats had their expression of MCTs determined by RT-PCR analysis. In essence, aerobic training is effective in maintaining SPA, but did not prevent the decline of aerobic capacity and anaerobic performance, leading us to propose that the decline of SPA is not fully attributed to a deterioration of physical properties. Changes in SPA were concomitant with changes in MCT1 expression in the soleus muscle of trained rats, suggestive of an additional adaptive response toward increased lactate clearance. This result is in line with our observation showing a better equilibrium on lactate production-remotion during the continuous exercise (LMT). We propose an approach to combat the decline of SPA of rats in their home cages. This new finding is worth for scientists who work with animal models to study the protective effects of exercise.

No MeSH data available.


Related in: MedlinePlus