Maximal lactate steady state in rats submitted to swimming exercise

Gobatto, Cláudio Alexandre; Mello, María Alice Rostom de; Sibuya, C. Y.; Azevedo, José Roberto Moreira de; Santos, Luciana Alves dos; Kokubun, Eduardo

doi:10.1016/s1095-6433(01)00362-2

Cited by 308 publications

(362 citation statements)

References 24 publications

Supporting

Mentioning

277

Contrasting

Unclassified

Order By: Relevance

“…The MLSS was found in the 5.2 ± 0.3 mmol/L concentration of blood lactate, at the intensity of 5.5% of body weight (BW); these results are similar to the ones obtained by Gobatto et al (20) (2001), who have found the MLSS of sedentary rats in the mean concentration of 5.5 mmol/L of blood lactate at the intensity of 5-6% of BW. Nonetheless, these values are different from the ones found by Manchado et al (21) (2005), who used the same principle of exercise with continuous loads in running exercise on treadmill.…”

Section: Adrenal Cholesterol Experimental Groupssupporting

confidence: 90%

“…It consisted of daily swimming efforts, five days/week, during three weeks, with overload of 0; 1 and 2% of body weight and duration of 1-5 min. The aim of the adaptation was to familiarize the rat to the liquid medium, to the increase attached to the torso and the exercise itself, with no promotion of physiological alterations concerning the physical training (20) .…”

Section: Adaptation To the Swimming Exercisementioning

confidence: 99%

“…Thinking about the existing gap in the literature concerning evaluation protocols in animals, our research group has been developing methods to precisely identify the individual exercise intensity for rats submitted to efforts in distinct ergometers, adapting tests already applied in humans to animal evaluation (20)(21) . Such research however, left the specific stress responses concerning different effort intensities unanswered.…”

Section: Introductionmentioning

confidence: 99%

“…The gold standard protocol for the identification of the metabolic aerobic/anaerobic transition during exercise both for humans and animals is the Maximal Lactate Steady State (MLSS) (20)(21)(22)(23) . The MLSS represents the highest intensity in which blood lactate stabilization occurs during continuous exercise, due to the balance between lactate production and its removal from the blood stream (20)(21)(23)(24) .…”

Section: Introductionmentioning

confidence: 99%

“…The MLSS represents the highest intensity in which blood lactate stabilization occurs during continuous exercise, due to the balance between lactate production and its removal from the blood stream (20)(21)(23)(24) .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Biomarcadores de estresse em ratos exercitados por natação em intensidades igual e superior à máxima fase estável de lactato

Contarteze

Manchado

Gobatto

et al. 2007

Rev Bras Med Esporte

Self Cite

View full text Add to dashboard Cite

Introduction:The level of stress during acute /chronic exercise is important, since higher levels of stress may impair animal welfare. The adrenocorticotrophic (ACTH) and corticosterone hormone concentrations, as well as cholesterol and ascorbic acid concentrations in adrenal gland, are considered an important stress biomarker. Purpose: To analyze the sensitivity of the different biomarkers during acute swimming exercise in different intensities performed by rats. Methods: Male Wistar adult rats (n = 18) previously adapted to swimming were submitted to three 25 min. swimming tests with loads of 5.0; 5.5 and 6.0% of their body weight (BW), for maximum lactate steady state (MLSS) determination. After MLSS attainment, the animals were divided into two groups: M (n = 9) sacrificed shortly after a 25 min. session of exercise at the MLSS intensity or S (n = 9) sacrificed after exhaustive exercise at intensity 25% above MLSS. For comparison purposes, a control group C (n = 10) was sacrificed in rest. Results: Serum ACTH and corticosterone concentrations were higher after exercise for the two groups (M and S) when compared with control group C (P < 0.05). The group S presented higher concentrations for both hormones in relation to the group M (P < 0.05). The concentrations of the cholesterol and ascorbic acid in adrenal were lower after exercise for the two groups (M and S) when compared with control group C (P < 0.05). No significant differences in adrenal ascorbic acid and cholesterol levels were observed when the two exercise intensities (M and S) were compared (P < 0.05). Conclusion: All biomarkers of HPA activity pointed alterations in the stress level of the rats submitted to acute swimming exercise. ACTH and corticosterone serum concentrations showed to be more sensitive to small alterations in the effort intensity.

show abstract

Section: Adrenal Cholesterol Experimental Groupssupporting

confidence: 90%

Section: Adaptation To the Swimming Exercisementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Biomarcadores de estresse em ratos exercitados por natação em intensidades igual e superior à máxima fase estável de lactato

Contarteze

Manchado

Gobatto

et al. 2007

Rev Bras Med Esporte

Self Cite

View full text Add to dashboard Cite

show abstract

MRP1/GS‐X pump ATPase expression: is this the explanation for the cytoprotection of the heart against oxidative stress‐induced redox imbalance in comparison to skeletal muscle cells?

Krause

Oliveira

Silveira

et al. 2006

Cell Biochemistry & Function

View full text Add to dashboard Cite

Striated muscle activity is always accompanied by oxidative stress (OxStress): the more intense muscle work and/or its duration, the more a redox imbalance may be attained. In spite of cardiac muscle functioning continuously, it is well known that the heart does not suffer from OxStress-induced damage over a broad physiological range. Although the expression of antioxidant enzymes may be of importance in defending heart muscle against OxStress, a series of combined antioxidant therapeutic approaches have proved to be mostly ineffective in avoiding cellular injury. Hence, additional mechanisms may be involved in heart cytoprotection other than antioxidant enzyme activities. The strong cardiotoxic effect of doxorubicin-induced cancer chemotherapy shed light on the possible role for multidrug resistance-associated proteins (MRP) in this context. Muscle activity-induced 'physiological' OxStress enhances the production of glutathione disulfide (GSSG) thus increasing the ratio of GSSG to glutathione (GSH) content inside the cells, which, in turn, leads to redox imbalance. Since MRP1 gene product (a GS-X pump ATPase) is a physiological GSSG transporter, adult Wistar rats were tested for MRP1 expression and activity in the heart and skeletal muscle (gastrocnemius), in as much as the latter is known to be extremely sensitive to muscle activity-induced OxS. MRP1 expression was completely absent in skeletal muscle. In contrast, the heart showed an exercise training-dependent induction of MRP1 protein expression which was further augmented (2.4-fold) as trained rats were challenged with a session of acute exercise. On the other hand, inducible expression of the 70-kDa heat shock protein (HSP70), a universal marker of cellular stress, was completely absent in the heart of sedentary and acutely exercised rats, whereas skeletal muscle showed a conspicuous exercise-dependent HSP70 expression, which decreased by 45% with exercise training. This effect was paralleled by a 58% decrease in GSH content in skeletal muscle which was even higher (an 80%-fall) after training thus leading to a marked redox imbalance ([GSSG]/[GSH] raised up to 38-fold). In the heart, GSH contents and [GSSG]/[GSH] ratio remained virtually unchanged even after exercise challenges, while GS-X pump activity was found to be 20% higher in the heart related to skeletal muscle. These findings suggest that an intrinsic higher capacity to express the MRP1/GS-X pump may dictate the redox status in the heart muscle thus protecting myocardium by preventing GSSG accumulation in cardiomyocytes as compared to skeletal muscle fibres.

show abstract

Acute exercise stimulates macrophage function: possible role of NF‐κB pathways

Silveira

Rodrigues

Krause

et al. 2006

Cell Biochemistry & Function

View full text Add to dashboard Cite

Moderate physical activity when performed on a regular basis presents a number of benefits to the whole organism, especially regarding immune system function, such as augmenting resistance to infections and to cancer growth. Although glutamine production by active muscle cells as well as neuroendocrine alterations mediated by the chronic adaptation to exercise may play a role, the entire mechanism by which exercise makes the immune system aware of challenges remains mostly uncovered. This is particularly true for the effects of an acute exercise session on immune function. In this work, circulating monocytes/macrophages from sedentary rats submitted to an acute (1 h) swimming session were tested for the ability of phagocytosing zymosan particles, phorbol miristate acetate (PMA)-induced hydrogen peroxide production, nitric oxide (NO) release (assessed by nitrate and nitrite production) and the expression of NO synthases (NOS-1, NOS-2 and NOS-3). The results showed that an exercise bout induced a 2.4-fold rise in macrophage phagocytic capacity (p ¼ 0.0041), a 9.6-fold elevation in PMA-induced hydrogen peroxide release into the incubation media (1-h, p ¼ 0.0022) and a 95.5%-augmentation in nitrite basal production (1-h incubation; p ¼ 0.0220), which was associated with a marked expression of NOS-2 (the inducible NOS isoform; p ¼ 0.0319), but not in other NOS gene products. Although NOS-2 expression is nuclear factor-kB (NF-kB)-dependent, no systemic oxidative stress was found, as inferred from the data of plasma TBARS and glutathione disulphide (GSSG) to glutathione (GSH) ratio in circulating blood erythrocytes which remained constant after the acute exercise. Also, no stressful situation seemed to be faced by monocytes/macrophages, since the expression of the 70-kDa heat shock protein (HSP70) remained unchanged. We conclude that NF-kB-dependent induction of NOS-2 and macrophage activation must be related to local factor(s) produced in the surroundings of monocytes/macrophages.

show abstract

Maximal lactate steady state in rats submitted to swimming exercise

Cited by 308 publications

References 24 publications

Biomarcadores de estresse em ratos exercitados por natação em intensidades igual e superior à máxima fase estável de lactato

Biomarcadores de estresse em ratos exercitados por natação em intensidades igual e superior à máxima fase estável de lactato

MRP1/GS‐X pump ATPase expression: is this the explanation for the cytoprotection of the heart against oxidative stress‐induced redox imbalance in comparison to skeletal muscle cells?

Acute exercise stimulates macrophage function: possible role of NF‐κB pathways

Contact Info

Product

Resources

About