Dataset Information

Resistance training and L-arginine supplementation are determinant in genomic stability, cardiac contractility and muscle mass development in rats.

ABSTRACT: L-arginine supplementation has been related to increased maximum strength and improvement of hemodynamic parameters in several diseases. The aim of our study was to evaluate the effect of L-arginine supplementation and resistance training on muscle mass, hemodynamic function and DNA damage in healthy rats subjected to a low-arginine concentration diet. Twenty three Wistar rats (290-320g) were divided into 4 groups: Sedentary (SED-Arg, n = 6), Sedentary+Arg (SED+Arg, n = 6), Resistance Training (RT-Arg, n = 5), Resistance Training+Arg (RT+Arg, n = 6). Trained animals performed resistance training protocol in a squat apparatus adapted for rats (4 sets of 10-12 repetitions, 90s of interval, 4x/week, 65-75% of One Maximum Repetition, for 8 weeks). Comet assay was performed to measure DNA damage in leukocytes. The resistance training induced higher muscle mass in trained groups. The L-arginine supplementation increased both gastrocnemius and left ventricle to body mass ratio and increased left ventricle contractility without changing hemodynamic variables. The SED+Arg group showed higher concentration of extracellular heat shock protein 72 (eHSP72) and total testosterone, as well as lower uric acid concentration in blood versus SED-Arg group. The administration of isolated L-arginine supplementation and its association with resistance training promoted less damage in leukocytes DNA. In conclusion, the L-arginine supplementation showed synergistic effect with resistance training regarding leukocyte genomic stability in a low-L-arginine diet scenario.

SUBMITTER: Stefani GP

PROVIDER: S-EPMC6160175 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Resistance training and L-arginine supplementation are determinant in genomic stability, cardiac contractility and muscle mass development in rats.

Stefani Giuseppe Potrick GP Marmett Bruna B Alves Jadson Pereira JP Möller Gabriella Berwig GB Heck Thiago Gomes TG Frizzo Matias Nunes MN Di Domenico Marlise M Motta Gabriela Almeida GA Dal Lago Pedro P Nunes Ramiro Barcos RB Rhoden Cláudia Ramos CR

PloS one 20180927 9

L-arginine supplementation has been related to increased maximum strength and improvement of hemodynamic parameters in several diseases. The aim of our study was to evaluate the effect of L-arginine supplementation and resistance training on muscle mass, hemodynamic function and DNA damage in healthy rats subjected to a low-arginine concentration diet. Twenty three Wistar rats (290-320g) were divided into 4 groups: Sedentary (SED-Arg, n = 6), Sedentary+Arg (SED+Arg, n = 6), Resistance Training ( ...[more]

PMID: 30261076

Similar Datasets

Project description:Wolframin (Wfs1) is a membrane protein of the sarco/endoplasmic reticulum. Wfs1 mutations are responsible for the Wolfram syndrome, characterized by diabetic and neurological symptoms. Although Wfs1 is expressed in cardiac muscle, its role in this tissue is not clear. We have characterized the effect of invalidation of Wfs1 on calcium signaling-related processes in isolated ventricular myocytes of exon5-Wfs1 deficient rats (Wfs1-e5/-e5) before the onset of overt disease. Calcium transients and contraction were measured in field-stimulated isolated myocytes using confocal microscopy with calcium indicator fluo-3 AM and sarcomere length detection. Calcium currents and their calcium release-dependent inactivation were characterized in whole-cell patch-clamp experiments. At 4 months, Wfs1-e5/-e5 animals were euglycemic, and echocardiographic examination revealed fully compensated cardiac function. In field-stimulated isolated ventricular myocytes, both the amplitude and the duration of contraction of Wfs1-e5/-e5 animals were elevated relative to control Wfs1+/+ littermates. Increased contractility of myocytes resulted largely from prolonged cytosolic calcium transients. Neither the amplitude of calcium currents nor their voltage dependence of activation differed between the two groups. Calcium currents in Wfs1-e5/-e5 myocytes showed a larger extent of inactivation by short voltage prepulses applied to selectively induce calcium release-dependent inactivation of calcium current. Neither the calcium content of the sarcoplasmic reticulum, measured by application of 20 mmol/l caffeine, nor the expression of SERCA2, determined from Western blots, differed significantly in myocytes of Wfs1-e5/-e5 animals compared to control ones. These experiments point to increased duration of calcium release in ventricular myocytes of Wfs1-e5/-e5 animals. We speculate that the lack of functional wolframin might cause changes leading to upregulation of RyR2 channels resulting in prolongation of channel openings and/or a delay in termination of calcium release.

Project description:Evidence from randomized controlled trials shows that exercise during cancer treatment benefits physical fitness, fatigue and quality of life. Since the effect of exercise on clinical outcome is currently unknown, exercise is not included as integral part of standard cancer care. Moreover, evidence regarding the optimal exercise prescription in terms of type and dose is lacking. To maintain quality of life in patients receiving palliative treatment with chemotherapy, toxicity-induced modifications in the prescribed chemotherapy dose are common. Such modifications - occurring in 40% of patients with metastatic colorectal cancer - may reduce benefit of treatment. The investigators hypothesize that exercise prevents chemotherapy dose modifications by reducing toxicity and enhancing psychological strength. Additionally, based on studies in rodents and preliminary data in patients with cancer, the researchers hypothesize that exercise has beneficial effects on the functionality of the natural killer cells, which play an important role in the innate immune defense against cancer. Both, fewer dose modifications and improved immune function may improve progression-free survival. This study is a three-armed trial comparing resistance exercise, aerobic interval exercise and usual care in patients with metastatic colorectal cancer to select the optimal exercise prescription for preventing chemotherapy dose modifications. The trial will use a Bayesian adaptive multi-arm multi-stage design with several interim analyses after which an ineffective study arm can be dropped early. This novel design makes the trial more efficient and reduces patients’ exposure to suboptimal study arms. Evidence regarding the exercise effects on i) clinical outcome, ii) the optimal exercise prescription, and iii) the underlying mechanisms, elucidates the potential of exercise to boost benefit from chemotherapy treatment. This evidence provides leads to improve progression-free survival and quality of life of patients suffering from one of the leading causes of cancer death worldwide.

Project description:The heterotrimeric cardiac troponin complex is a key regulator of contraction and plays an essential role in conferring Ca2+ sensitivity to the sarcomere. During ischemic injury, rapidly accumulating protons acidify the myoplasm, resulting in markedly reduced Ca2+ sensitivity of the sarcomere. Unlike the adult heart, sarcomeric Ca2+ sensitivity in fetal cardiac tissue is comparatively pH insensitive. Replacement of the adult cardiac troponin I (cTnI) isoform with the fetal troponin I (ssTnI) isoform renders adult cardiac contractile machinery relatively insensitive to acidification. Alignment and functional studies have determined histidine 132 of ssTnI to be the predominant source of this pH insensitivity. Substitution of histidine at the cognate position 164 in cTnI confers the same pH insensitivity to adult cardiac myocytes. An alanine at position 164 of cTnI is conserved in all mammals, with the exception of the platypus, which expresses a proline. Prolines are biophysically unique because of their innate conformational rigidity and helix-disrupting function. To provide deeper structure-function insight into the role of the TnC-TnI interface in determining contractility, we employed a live-cell approach alongside molecular dynamics simulations to ascertain the chemo-mechanical implications of the disrupted helix 4 of cTnI where position 164 exists. This important motif belongs to the critical switch region of cTnI. Substitution of a proline at position 164 of cTnI in adult rat cardiac myocytes causes increased contractility independent of alterations in the Ca2+ transient. Free-energy perturbation calculations of cTnC-Ca2+ binding indicate no difference in cTnC-Ca2+ affinity. Rather, we propose the enhanced contractility is derived from new salt bridge interactions between cTnI helix 4 and cTnC helix A, which are critical in determining pH sensitivity and contractility. Molecular dynamics simulations demonstrate that cTnI A164P structurally phenocopies ssTnI under baseline but not acidotic conditions. These findings highlight the evolutionarily directed role of the TnI-cTnC interface in determining cardiac contractility.

Dataset Information

Resistance training and L-arginine supplementation are determinant in genomic stability, cardiac contractility and muscle mass development in rats.

Publications

Resistance training and L-arginine supplementation are determinant in genomic stability, cardiac contractility and muscle mass development in rats.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets