Table of Contents    
ORIGINAL ARTICLE
Year : 2019  |  Volume : 10  |  Issue : 3  |  Page : 140-143  

Effect of interval and continuous training on proliferator-activated receptor gamma coactivator-1α and lactate dehydrogenase B levels in adult rat heart


1 Department of Medical Physiology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
2 Department of Biochemistry and Molecular Biology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia

Date of Web Publication14-Jan-2020

Correspondence Address:
Ermita I Ibrahim Ilyas
Jalan Salemba Raya No. 6, Jakarta Pusat 10430
Indonesia
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/jnsbm.JNSBM_69_19

Rights and Permissions
   Abstract 


Introduction: Mitochondrial biogenesis is affected by peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and can be induced through physical exercise. Lactate from the skeletal muscle produced in the heart during exercise can be used as an energy source through conversion by lactate dehydrogenase B (LDH B). This study compared the effects of continuous training (CT) and interval training (IT) on PGC-1α and LDH B levels in the adult rat hearts. Materials and Methods: Fifteen male adult Wistar rats (12 months old) were randomly divided into three groups as follows: A control Group (c), a CT group and an IT group. Training was conducted using a rodent treadmill, 5 days/week for 8 weeks. The duration was 50 min for the CT group. In the IT group, training consisted of 4 bouts of 4 min of exercise, followed by rest intervals of 1 min. Speed was increased each week. After 8 weeks of training, the rats were sacrificed, and the levels of PGC-1α and LDH B in heart tissue were measured using enzyme-linked immunosorbent assay. Results: Differences in PGC-1α levels between groups were statistically significant (P = 0.008), while differences in LDH B levels were not statistically significant (P = 0.063). Levels of PGC-1α and LDH B were higher in the CT group than in the IT group. Conclusion: We concluded that CT has a greater effect on energy metabolism in the heart than IT.

Keywords: Continuous training, heart, interval training, lactate dehydrogenase B, proliferator-activated receptor gamma coactivator-1α


How to cite this article:
Soeria Santoso DI, Handayani T, Mareta DE, Paramita N, Jusman SA, Ibrahim Ilyas EI. Effect of interval and continuous training on proliferator-activated receptor gamma coactivator-1α and lactate dehydrogenase B levels in adult rat heart. J Nat Sc Biol Med 2019;10, Suppl S1:140-3

How to cite this URL:
Soeria Santoso DI, Handayani T, Mareta DE, Paramita N, Jusman SA, Ibrahim Ilyas EI. Effect of interval and continuous training on proliferator-activated receptor gamma coactivator-1α and lactate dehydrogenase B levels in adult rat heart. J Nat Sc Biol Med [serial online] 2019 [cited 2020 Aug 4];10, Suppl S1:140-3. Available from: http://www.jnsbm.org/text.asp?2019/10/3/140/275598




   Introduction Top


Heart function requires considerable energy production through oxidative phosphorylation in mitochondria. Peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) is a transcriptional coactivator that functions as the main regulator for mitochondrial biogenesis and cardiac metabolism. The expression of PGC-1α can be induced through physical exercise.[1],[2] Frequency, intensity, time or duration, and type of physical exercise can have variable effects.[3] Interval training (IT) consists of high intensity, short to longer bouts of exercise (equal to or greater than maximum steady-state lactate levels), interspersed with recovery periods (light exercise or rest).[4] Continuous training (CT) is performed over a long exercise period. Both of these exercises are believed to improve mitochondrial biogenesis through its main regulator PGC-1α.[5] The lactate from the skeletal muscle produced during physical exercise can be used as an energy source in the heart and will be converted by lactate dehydrogenase (LDH).[6],[7] LDH is a tetrameric enzyme that catalyzes the lactate-pyruvate reaction and consists of two subunits types: M (muscle) or LDH A and H (heart) or LDH B. These two subunits can form five possible tetramers (isoenzymes): H4, M4, and three mixed tetramers (MH3, M2H2, and M3H). LDH A converts pyruvate to lactate and is expressed in the skeletal muscle, while LDH B converts lactate to pyruvate and is expressed more in the heart muscle.[7],[8],[9] PGC-1α is induced through exercise and can increase LDH activity in the skeletal muscle and heart.[8],[9] Several studies showed that LDH B activity was increased after exercise, but others showed decreased or unchanged LDH B activity. Factors that can influence this activity include the intensity and duration of exercise, subject or animal fitness, and the type of exercise.[10] Therefore, the aim of this study was to compare the effect of interval versus continuous training on proliferator activated receptor gamma coactivator-1α (PGC-1α) and lactate dehydrogenase B (LDH B) levels in adult rat heart.


   Materials and Methods Top


Animals

This in vivo experimental study was approved by the University of Indonesia Ethics Committee. Fifteen male Wistar rats (12 month old), weighing 300–400 g, were evenly and randomly divided into a control group without treatment (C), a CT group and an IT group. With access to water and food ad libitum, the rats were placed in a clean room with the temperature maintained at 23°C, using a 12 h day/night cycle. Acclimatization to the cage environment was performed for 5 days.

Exercise treatment

Before the start of treatment, the animals were acclimatized for 5 days to the treadmill speed of 15 m/min, 10 min/day. From the following week until the 8th week, the CT group was given 50 min of exercise that consisted of warming up for 5 min at 6 m/min, followed by 40 min of continuous running on the treadmill, speed was gradually increased from 9 m/min in the 1st week to 15 m/min in the last week, and ended with a cooling down period at 6 m/min for 5 min. The IT group was given 30 min of exercise that consisted of warming up for 5 min at 6 m/min, followed by 20 min of exercise (4 bouts of 4 min at higher intensity, gradually increased from 16 m/min in the 1st week to 25 m/min in the last week, with rest intervals of 1 min), and cooling down for 5 min at 6 m/min. Both training protocols were performed for 5 days per week for 8 weeks. This physical exercise protocol was used in a previous preliminary study measuring plasma lactate levels.[5],[6],[11]

Sample collection and measurement of proliferator-activated receptor gamma coactivator-1α and lactate dehydrogenase B levels

At the end of the 8th week, the animals were sacrificed, and the hearts were isolated and stored at −80°°C. Homogenates were made according to the working protocol of each enzyme-linked immunosorbent assay kit using left ventricular myocardium. A Bradford test was performed to measure total protein levels. An ELISA kit (Cusabio; CSB-EL018425RA) was used to measure PGC-1α levels, with another ELISA kit (MyBioSource; MBS764976) used to measure LDH B levels.

Statistical analysis

Data analysis was performed with SPSS, Statistics Package for the Social Sciences program (SPSS, Inc., Chicago, USA) for windows; preliminary analysis was performed with the Shapiro–Wilk test to confirm the normality of data distribution, followed by the determination of homogeneity of variation. One-way analysis of variance (ANOVA) was used, with a P < 0.05 as the criterion for statistical significance. A post hoc Games-Howell test was used to show significant differences between groups.


   Results Top


Measurement of proliferator-activated receptor gamma coactivator-1α levels

After 8 weeks of exercise, the heart tissue level of PGC-1α in the CT group (36.78 ± 2.26 pg/mg total protein) was higher than that in the IT group (24.10 ± 1.19 pg/mg total protein) and C group (22.79 ± 7.22 pg/mg total protein). Differences in PGC-1α levels between groups were statistically significant (P = 0.008; ANOVA) [Figure 1]. A post hoc Games-Howell test showed significant differences between CT and IT groups (P = 0.006).
Figure 1: Proliferator-activated receptor gamma coactivator-1α level after 8 weeks of treatment. Data mean standard error, P < 0.01 between groups. A post hoc Games-Howell test showed P < 0.01 between continuous training versus interval training

Click here to view


Measurement of lactate dehydrogenase B levels

After 8 weeks of exercise, the heart tissue level of LDH B in the C group (2.32 ± 0.27 ng/mg total protein) was higher than that in the CT group (2.18 ± 0.11 ng/mg total protein); and IT group (1.72 ± 0.12 ng/mg total protein), but the difference were not statistically significant (P = 0.063; ANOVA) [Figure 2].
Figure 2: Lactate dehydrogenase B levels after 8 weeks of treatment. Data mean standard error, P > 0.05 (not significant)

Click here to view



   Discussion Top


In our study, the level of PGC-1α was higher in the CT group than in the IT and C groups. PGC-1α activity and expression are very sensitive to extracellular and physiological cues.[2],[12] During physical exercise, skeletal muscle contraction will increase, and Ca 2+ influx will activate calcium/calmodulin-dependent protein kinase, phosphorylate cAMP response element-binding protein, and activate PGC-1α. In addition, an increase in ATP energy requirements will activate 5' AMP-activated protein kinase (AMPK) signals that can phosphorylate PGC-1α directly. In the heart, PGC-1α will bind to transcription factors, including estrogen-related receptor, peroxisome proliferator-activated receptors and nuclear respiratory factor; this will activate genes that express key enzymes involved in fatty acid oxidation, fatty acid transport, and lactate metabolism.[1],[2],[12] A long duration of CT at low speed allows the heart to use energy through aerobic fatty acid oxidation. An increase in AMPK during muscle contraction will reduce malonyl-CoA formation and accelerate fatty acid oxidation because resistance to carnitine palmitoyltransferase 1 does not occur.[13],[14] Oxidation and uptake of fatty acid were higher with 60 min of exercise than with 30 min of exercise,[15] and more fatty acid oxidation occurred during moderate exercise at 65% of VO2,peak than during exercise at 25% or 85% of VO2, peak.[16] This is because cardiomyocytes have a high capacity for fatty acid oxidation and oxygen consumption. Overexpression of PGC-1α in vivo is associated with an increase in O2 capacity and fatty acid oxidation.[2] Fatty acid oxidation will produce 60%–90% of energy needs in the heart.[14]

IT, consisting of short duration, high-intensity exercise, uses anaerobic metabolism to produce energy through glycolysis.[4] An increase in heart rate also gradually changes the supply of energy, with a shift to carbohydrate or blood glucose metabolism.[17] Therefore, IT with higher intensity and shorter duration can increase glucose oxidation.[5] In addition, PGC-1α mRNA expression during IT is only temporary, with a relatively short half-life (20 min) before undergoing ubiquitination and proteasome degradation.[5],[12] PGC-1α will increase >10-fold within 4 h after the last training session and return to the baseline level within 24 h of recovery.[18] In this study, we measured PGC-1α levels more than 24 h after the last training session; this may account for the low level obtained with IT.

During exercise, energy requirements in skeletal muscle will increase rapidly through glycolysis and glycogenolysis, leading to lactate production. Lactate will be released into the circulation and accumulate if not taken up by tissue.[4],[6] Lactate is a potential energy source in the heart.[14],[19] Lactate derived from the skeletal muscle will be taken up by the heart by monocarboxylate transporter 1 into the mitochondria. Once inside the mitochondria, lactate will be converted to pyruvate by LDH B. Pyruvate will be oxidized by pyruvate dehydrogenase to acetyl CoA, which will enter the tricarboxylic acid cycle to produce energy.[7],[8] LDH B is widely expressed in oxidative fibers, especially in the heart.[7],[8],[9] Normally, LDH is stored at low-levels in the tissue, but stimulation in the form of exercise can cause an increase in lactate catalyzed by LDH B.[6],[20] Several studies have suggested that LDH B is a downstream target of PGC-1α induced by exercise in the skeletal muscle,[9] and heart muscle.[8] However, the mechanism is still unclear. Many factors influence enzyme activity, including the intensity and duration of exercise, subject fitness, and type of exercise.[10] Other studies found that extreme exercise can increase the risk of damage in heart myocytes, with high LDH levels detectable in plasma and heart tissue.[20]

In this study, LDH B levels in both CT and IT groups were lower than those in controls. Levels of LDH B were higher in the CT group than in the IT group. It was thought that the supply of energy from fatty acids predominated during CT, with the use of lactate as an energy source less than that in IT, due to low lactate production. Continuous prolonged exercise can suppress oxidation of glucose and reduce lactate oxidation.[21] However, in IT, higher intensity exercise will cause anaerobic glycolysis in the skeletal muscles, which increases blood lactate accumulation. However, in the rest period between exercise bouts, this lactate can be taken up by tissue to be oxidized, contributing to increased lactate clearance (minimal with a 30 s rest). Furthermore, IT can increase the activity of LDH,[6] which may cause increased use of LDH B, leading to a decrease of LDH B in tissue. In CT, the levels of PGC-1α and LDH B are higher than those in IT during energy metabolism in the heart tissue. However, the mechanism is still unclear, and further research is needed.

Financial support and sponsorship

Publikasi Terindeks Untuk Tugas Akhir Mahasiswa Universitas Indonesia (PITTA UI 2018) Grant.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Di W, Lv J, Jiang S, Lu C, Yang Z, Ma Z, et al. PGC-1: The energetic regulator in cardiac metabolism. Curr Issues Mol Biol 2018;28:29-46.  Back to cited text no. 1
    
2.
Lehman JJ, Barger PM, Kovacs A, Saffitz JE, Medeiros DM, Kelly DP. Peroxisome proliferator-activated receptor gamma coactivator-1 promotes cardiac mitochondrial biogenesis. J Clin Invest 2000;106:847-56.  Back to cited text no. 2
    
3.
American College of Sports Medicine. ACSM's Guidelines for Exercise Testing and Prescription. Thompson WR, editor. 8th ed. Atlanta: Lippincott Williams & Wilkins; 2009. p. 17-215.  Back to cited text no. 3
    
4.
Billat LV. Interval training for performance: A scientific and empirical practice. Special recommendations for middle-and long-distance running. Part I: Aerobic interval training. Sports Med 2001;31:13-31.  Back to cited text no. 4
    
5.
Hafstad AD, Boardman NT, Lund J, Hagve M, Khalid AM, Wisløff U, et al. High intensity interval training alters substrate utilization and reduces oxygen consumption in the heart. J Appl Physiol (1985) 2011;111:1235-41.  Back to cited text no. 5
    
6.
Mohebbi H, Rahmani-nia F, Riasi A, Marandi M. The effects of interval training and age on blood lactate (La) levels and lactate dehydrogenase (LDH) activity in male wistar rats. J Med Sci 2015;12:37-45.  Back to cited text no. 6
    
7.
Gladden LB. A lactatic perspective on metabolism. Med Sci Sports Exerc 2008;40:477-85.  Back to cited text no. 7
    
8.
Liang X, Liu L, Fu T, Zhou Q, Zhou D, Xiao L, et al. Exercise inducible lactate dehydrogenase B regulates mitochondrial function in skeletal muscle. J Biol Chem 2016;291:25306-18.  Back to cited text no. 8
    
9.
Summermatter S, Santos G, Pérez-Schindler J, Handschin C. Skeletal muscle PGC-1α controls whole-body lactate homeostasis through estrogen-related receptor α-dependent activation of LDH B and repression of LDH A. Proc Natl Acad Sci U S A 2013;110:8738-43.  Back to cited text no. 9
    
10.
Gail J, Tuig V. Effects of Age, Training and Exercise on Plasma Lactate Dehydrogenase Activity in Male Rats. Ames: IOWA State University; 1976.  Back to cited text no. 10
    
11.
Manchado FD, Gobatto CA, Contarteze RV, Papoti M, De Mello MA. Maximal lactate steady state in running rat. ASEP 2005;8:29-35.  Back to cited text no. 11
    
12.
Rowe GC, Jiang A, Arany Z. PGC-1 coactivators in cardiac development and disease. Circ Res 2010;107:825-38.  Back to cited text no. 12
    
13.
Dolinsky VW, Dyck JR. Role of AMP-activated protein kinase in healthy and diseased hearts. Am J Physiol Heart Circ Physiol 2006;291:H2557-69.  Back to cited text no. 13
    
14.
Stanley WC, Recchia FA, Lopaschuk GD. Myocardial substrate metabolism in the normal and failing heart. Physiol Rev 2005;85:1093-129.  Back to cited text no. 14
    
15.
Horowitz JF, Klein S. Lipid metabolism during endurance exercise. Am J Clin Nutr 2000;72:558S-63.  Back to cited text no. 15
    
16.
Jeppesen J, Kiens B. Regulation and limitations to fatty acid oxidation during exercise. J Physiol 2012;590:1059-68.  Back to cited text no. 16
    
17.
Coyle EF. Physical activity as a metabolic stressor. Am J Clin Nutr 2000;72:512S-20S.  Back to cited text no. 17
    
18.
Perry CG, Lally J, Holloway GP, Heigenhauser GJ, Bonen A, Spriet LL. Repeated transient mRNA bursts precede increases in transcriptional and mitochondrial proteins during training in human skeletal muscle. J Physiol 2010;588:4795-810.  Back to cited text no. 18
    
19.
Goodwin GW, Taegtmeyer H. Improved energy homeostasis of the heart in the metabolic state of exercise. Am J Physiol Heart Circ Physiol 2000;279:H1490-501.  Back to cited text no. 19
    
20.
Nikbakht H, Abdi A, Ebrahim K. Heart and plasma LDH and CK in response to intensive treadmill running and aqueous extraction of Red crataegus pentaegyna in male rats. Eur J Exp Biol 2014;4:369-74.  Back to cited text no. 20
    
21.
Donovan CM, Brooks GA. Endurance training affects lactate clearance, not lactate production. Am J Physiol 1983;244:E83-92.  Back to cited text no. 21
    


    Figures

  [Figure 1], [Figure 2]



 

Top
  
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
   Introduction
    Materials and Me...
   Results
   Discussion
    References
    Article Figures

 Article Access Statistics
    Viewed288    
    Printed9    
    Emailed0    
    PDF Downloaded41    
    Comments [Add]    

Recommend this journal