Orientador: Roberto Carlos Burini / Banca: Nailza Maesta / Banca: Kátia Cristina Portero McLellan / Banca: Fábio Lera Orsatti / Banca: Leone Simonetti / Resumo: Introdução: A erva mate (Ilex Paraguariensis) é uma bebida consumida principalmente na América do Sul e contém componentes com função antioxidante e possíveis propriedades ergogênicas. Sabe-se que o exercício eleva o estresse oxidativo e a lesão muscular, portanto o consumo do chá mate poderia proporcionar efeitos benéficos. Objetivo: Avaliar o efeito do consumo agudo de chá mate nos parâmetros de estresse oxidativo e lesão muscular em jogadoras de futebol profissional que foram expostas ao exercício exaustivo. Métodos: Quinze jogadoras de futebol (22,1 ± 4,2 anos) foram avaliadas de forma randomizada consumindo 5g de chá mate solúvel (400 ml) ou 400 ml de água em estudo cruzado com 7 dias de washout. Ambas as bebidas foram fornecidas após jejum noturno e 60 minutos antes de um teste incremental de esteira até a exaustão. Todos os indivíduos ingeriram 30g de maltodextrina 30 minutos antes do início do teste. Por meio do desempenho no teste de esteira do grupo água, foram criados dois subgrupos com os indivíduos com o melhor tempo de esteira (MTE, n=8) e os outros com pior tempo de esteira (PTE, n=7). Amostras sanguíneas foram coletadas em jejum, pré e pós-exercício, sendo avaliados marcadores de lesão muscular (CK, AST and ALT), antioxidante (TAP e ácido úrico), estresse oxidativo (MDA) e anaerobiose (lactato). Foi utilizado ANOVA de medidas repetidas para comparar as variáveis basal, pré e pós exercício; e teste-t dependente para comparar os valores de delta (final-inicial) ( ) e o tempo de esteira entre os grupos chá e água. Resultados: Quando foram avaliados todos os indivíduos, notou-se maior concentração de lactato e redução das concentrações de ALT no grupo chá mate. No grupo PTE, quando houve consumo de chá mate notou-se maior tempo de esteira, lactato e ácido úrico do que o grupo que consumiu água. No grupo MTE não foi observado aumento das concentrações... / Abstract: Background: Yerba mate tea (Ilex Paraguariensis) is an herbal tea beverage consumed mainly in South America that presents components with antioxidant, antinflammatory, and possible ergogenic properties. It is known that exercise increases oxidative stress and muscle damage, and then mate tea intake could show beneficial effects. Purpose: To evaluate the effect of acute intake of yerba mate on blood markers of oxidative stress and muscle damage in female soccer players exposed to exhaustive exercise. Methods: 15 female soccer players (22.1 ± 4.2 years old) were studied randomized with either 5g of soluble yerba mate (400 ml) or 400 ml of water cross-overly with 7 days of washout. Both liquids were given after an overnight fasting and before 60 minutes of a treadmill incremental test up to exhaustion. All subjects were fed with 30g of maltodextrin 30 minutes before the beginning of the test. From the treadmill performance of the drinking-water players it was evaluated all the individuals and also was created the sub groups of Higher Run Time (HRT, n=8) and the others (WRT, n=7). Blood samples were collected before and immediately post-exercise and assayed for markers of tissue integrity (enzymes CK, AST and ALT), antioxidants (TAP and uric acid), oxidants (MDA) and anaerobiosis (lactate). It was used repeated-measures ANOVA to compare the variables in basal, pre and post-exercise; and t-test dependent to compare the delta (final-initial) values ( ) and time of treadmill run between groups, for p<0.05. Results: In all the individuals it was noted higher lactate and lower ALT levels after the exercise in mate group. The yerba mate tea group showed longer treadmill run along with higher increase of lactate and uric acid than the water group in the WRT sub group. In HRT it was observed no increase in AST and lower ALT levels in mate tea group. Conclusion: Yerba mate intake by female soccer players increased tolerance to exhaustive exercise ... / Doutor

Orientador: Roberto Carlos Burini / Coorientador: Erick Prado de Oliveira / Banca: Fernando Moreto / Banca: Nailza Maestá / Resumo: O futebol é um esporte com característica intermitente pela realização de esforços de alta intensidade e curta duração, interposto por períodos de menor intensidade e duração variável. As atividades dos jogadores durante a temporada competitiva são intensas, podendo promover alterações metabólicas, principalmente no músculo esquelético. As elevadas contrações musculares excêntricas induzem danos e respostas inflamatórias, que podem influenciar a produção de espécies reativas de oxigênio (EROs) durante e depois de esforço no futebol. Além disso, o exercício exaustivo promove danos musculares, que são induzidos principalmente por estresse mecânico resultando em aumento substancial de proteínas intracelulares no plasma. Diversas pesquisas estão sendo realizadas para descobrir se a ingestão de antioxidantes possa prevenir os danos causados pelo exercício exaustivo, melhorando o processo de recuperação do exercício. A quercetina é um composto de flavonoides que tem sido investigada por apresentar benefícios para saúde, além de propriedades ergogênicas. Suas atividades biológicas estão ligadas a capacidade antioxidante e anti-inflamatória. Dentre suas diversas funções, a quercetina parece aumentar a atividade de enzimas antioxidantes naturais como a superóxido dismutase e catalase. Também age inibindo a ação da xantina oxidase, principal fonte de EROs durante exercícios intensos de curta duração, atenuando o estresse oxidativo e resposta inflamatória, principalmente in vitro. Seu efeito no desempenho está relacionado com o aumento do processo de biogênese mitocondrial por meio das vias de sinalização intracelular. Apesar dos resultados controversos na literatura acerca do efeito ergogênico da quercetina, as meta-análises existentes indicam que há pequeno, porém significante benefício no desempenho / Abstract: The soccer is a sport with intermittent feature for conducting efforts of high intensity and short duration, brought by periods of lower intensity and variable duration. The activities of the players during the competitive season are intense and may promote metabolic changes, particularly in skeletal muscle. The high eccentric muscle contractions induce damage and inflammatory responses, which may influence the production of reactive oxygen species (ROS) during and after an effort in soccer. Furthermore, the exhaustive exercise promotes muscle damage which are mainly driven by mechanical stress resulting in a substantial increase of intracellular proteins in plasma. Several studies are being conducted to find out if the intake of antioxidants may prevent damage caused by exhaustive exercise, improving the process of recovery from exercise. Quercetin is a flavonoid compound which has been investigated for presenting health benefits beyond ergogenic properties. Their biological activities are linked to antioxidant capacity and anti inflammatory. Among its many functions, quercetin appears to increase the activity of natural antioxidant enzymes such as superoxide dismutase and catalase. Also acts by inhibiting the action of xanthine oxidase, the main source of ROS during intense exercise of short duration, attenuating oxidative stress and inflammatory response, especially in vitro. Its effect on performance associated with increased mitochondrial biogenesis process by means of intracellular signaling pathways. Despite the controversial results in the literature about the ergogenic effect of quercetin, existing meta-analyzes indicate that there is a small but significant performance benefit / Mestre

Thesis (MSc (Physiological Sciences))--University of Stellenbosch, 2006. / Despite a growing interest into the mechanisms of the repeated bout effect, little is known about the consequences of chronic eccentrically biased training and the possible advantageous such training may offer to athletes as well as patients with muscle-debilitating disease. This study investigated the role of satellite cells in the muscle adaptation in response to either downhill or uphill high intensity training (HIT). Welltrained endurance runners were divided into two training groups matched for training volume and 10 km running times (n = 6, uphill training, UP; n = 6, downhill training, DH) and subjects in both groups completed 10 HIT sessions over a period of 4 weeks. Running performance was tested before and after the training intervention by a 10 km road race and peak treadmill speed (PTS) in horizontal and inclined (+5%) laboratory incremental tests to exhaustion. Skeletal muscle biopsies were sampled at baseline, after 2 HIT sessions, and after 4 weeks of HIT. Muscle was analysed immunohistochemically for satellite cell frequency as identified by CD56 and M-cadherin (Mcad) expression. Myogenin protein contents of muscle homogenates were determined by western blotting. Myosin heavy chain (MyHC) isoform proportions and mean fibre crosssectional area was measured. During the HIT intervention, UP exercised at a higher percentage of their HRmax than DH (mean ± SD, 97 ± 1 vs. 92 ± 3 %HRmax, p < 0.005), but at a similar rate of perceived exertion (RPE). DH completed more intervals per session and covered greater distance per session than their UP counterparts. Both training groups increased their training intensity but decreased their training volume during the 4 weeks of HIT. The combined group of 12 athletes improved their PTSgradient (mean ± SD, 16.7 ± 0.8 vs. 17.3 ± 1.0 km/h, p < 0.05). No significant differences between groups were found for PTS, VO2max or 10 km performance. Satellite cell frequency in this cohort of trained runners (48.9 ± 10.3 km/week) at baseline was similar to healthy young males (CD56+ cells/fibre, 0.19 ± 0.10). Satellite cell frequency increased significantly in DH after 4 weeks (Mcad, 123%; CD56, 138%) and non-significantly in UP (Mcad, 45%, CD56, 39%). No significant differences were found after two training sessions or at any time between groups. Mcad and CD56 expression correlated well (r = 0.95, p < 0.0001). Muscle myogenin content increased for both groups (UP: 56%; DH: 60%) after 4 weeks. No notable changes were seen after two training sessions. However, myogenin levels 2 days after session 1 correlated well (r= 0.99, p<0.005) with muscle pain experienced on the same day, as measured by the visual analogue scale. No changes were seen in the MyHC proportions or the fibre cross-sectional area after the training intervention. It was concluded that the training intervention was too short to induce changes in MyHC distribution or fibre area. Is seems likely that satellite cell proliferation was initiated as an early response to DOMS, but the response was maintained for 4 weeks. However, due to the lack of change in fibre morphology and myonuclear number, the role of satellite cell proliferation in fibre type transformation or muscle hypertrophy could not be established. Similarly, various possible roles for increased myogenin protein are offered, but since the origin of myogenin expression (satellite cells vs. myonuclei) was not determined, no definite conclusion regarding the precise function can be made. In conclusion, this study is the first to definitively indicate satellite cell proliferation in well-trained endurance runners in response to a change in training, including specifically downhill HIT. This response was early and sustained. This study asks several questions about the role of satellite cells during muscle adaptation to repetitive downhill training, and lays a foundation for further research into this unexplored field.

Orientadores: Admar Costa de Oliveira, Roberto Carlos Burini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-09-11T21:09:22Z (GMT). No. of bitstreams: 1 Haidamus_LeandroLopes_D.pdf: 785768 bytes, checksum: a63544a849a7db50b64812194be804ca (MD5) Previous issue date: 2007 / Resumo: O uso de drogas antiinflamatórias é comum entre atletas nos quais a prevalência de lesões musculares é elevada tanto nos períodos de treinamento e competição. Entretanto, algumas dessas drogas possuem ação imunossupressiva, que quando utilizadas em grande quantidade ou por tempo prolongado pode provocar queda nas respostas imunológicas. O objetivo da presente Tese foi verificar se a suplementação com ácidos graxos poliinsaturados ômega-3 ocasionaria uma redução, tanto nas concentrações plasmáticas dos indicadores de lesão muscular (enzima lactato desidrogenase e creatina quinase) como dos mediadores químicos da inflamação da série ¿2¿ (prostaglandina E2, tromboxano B2 e leucotrieno B4) derivados do ácido araquidônico (C20:4, ?-6) e das alterações morfológicas do músculo esquelético. O experimento foi desenvolvido com 36 ratos Wistar distribuídos ao acaso em quatro grupos experimentais com nove ratos. Os grupos formados eram os seguintes: Grupo 1 - ratos sedentários sem suplementação; Grupo 2 - ratos sedentários com suplementação; Grupo 3 - ratos submetidos às sessões de natação (60 minutos diários), com carga de peso extra crescente, sem suplementação e Grupo 4 ¿ ratos submetidos às sessões de natação, com carga de peso extra crescente, com suplementação. A suplementação era feita por gavagem utilizando-se 3,0 g diárias de óleo de peixe contendo AGPI ?-3 (EPA: 187,0 mg/g e DHA: 140,0 mg/g) durante 28 dias. Os grupos não suplementados receberam 3,0 g de azeite de oliva diariamente (grupo controle). Os ratos receberam dieta não purificada de fórmula fechada (MP-77- Primor) e água à vontade, sendo os pesos avaliados semanalmente. Os indicadores de lesão muscular (LDH e CK), análise histológica e morfométrica das fibras musculares esqueléticas bem como os mediadores do processo inflamatório (PGE2, TXB2 e LTB4) foram determinados no final do experimento. Os resultados obtidos indicam que a suplementação com AGPI ?-3 reduziu a concentração plasmática da enzima LDH, tanto nos animais sedentários como nos submetidos ao treinamento físico (p<0,05). Com relação aos mediadores químicos da inflamação (PGE2, TXB2 e LTB4) as concentrações plasmáticas reduziram significativamente (p<0,05) nos animais sedentários, mas não reduziram nos animais submetidos ao exercício físico. No entanto, ao se observar esse resultado, verificou-se que em todos os mediadores químicos houve uma redução nos valores absolutos nos animais suplementados com AGPI ?-3. Pela análise histológica das fibras musculares mostrou que nos grupos treinados, os ratos não suplementados apresentaram as seguintes alterações morfológicas: presença de processo de fagocitose de fibra muscular, fibra atrófica e fibras polimórficas, enquanto que nos ratos suplementados, a análise histológica mostrou uma redução acentuada dessas alterações o que resultou na quase inexistência de lesões musculares. Tendo em vista os resultados obtidos, pode ser sugerido de que ação antiinflamatória dos AGPI ?-3 nos ratos e por extensão em atletas, seria maior se a suplementação fosse realizada diariamente independentemente do período de treinamento / Abstract: The use of antiinflammatory drugs is common among athletes in which the prevalence of muscular lesions is elevated in training and competition periods. However, some of those drugs have an immunosuppression action, and when used in high dosages or for long time can provoke a decrease in the immunological responses. The objective of the present Thesis was to verify if the supplementation with polyunsaturated fatty acids omega-3 would cause a reduction, in the plasmatic concentrations of the indicators of muscular lesion (lactate dehidrogenase enzyme and creatine kinase) as well as in the chemical mediators of the inflammation of the series ¿2¿ (prostaglandin E2, thromboxane B2 and leukotriene B4) derived of arachidonic acid (C20:4, ?-6) and the morphologic alterations of skeletal muscle. The experiment was developed with 36 Wistar rats distributed at random in four experimental groups with nine rats. The formed groups were the following: Group 1 - sedentary rats without supplementation; Group 2 - sedentary rats with supplementation; Group 3 - rats submitted to swimming sessions (60 minutes daily), with load of gaining extra weight, without supplementation and Group 4 - rats submitted to swimming sessions, with load of gaining extra weight, with supplementation. The supplementation was made daily by ¿gavage¿ using 3,0g of fish oil containing AGPI ?-3 (EPA: 187,0 mg/g and DHA: 140,0 mg/g) for 28 days. The groups not supplemented received 3,0g of olive oil daily (control group). The rats received a non-purified diet of closed formula (MP-77-Primor) and water was ad libitum, with their weight being checked weekly. The indicators of muscular lesion (LDH and CK), histological and morphometric analyses of the skeletal muscular fibers as well as the mediators of the inflammatory process (PGE2, TXB2 and LTB4) were determinated at the end of the experiment. The obtained results indicate that the supplementation with AGPI ?-3 did reduce the plasmatic concentration of the LDH enzyme in the sedentary animals as well as in the animals submitted to the physical training (p<0,05). With respect to the chemical mediators of the inflammation (PGE2, TXB2 and LTB4) the plasmatic concentrations were reduced significantly (p < 0,05) in the sedentary animals, but were not reduced in the animals submitted to the physical exercise. However, by observing this results, it was verified that in all of the chemical mediators there was a reduction in the absolute values in the supplemented animals with AGPI ?-3. By the histological analysis of the muscular fibers showed that in the trained groups, the no supplemented rats had the following morphologic alterations: presence of the process of phagocytosis of muscular fiber, atrophic fiber, polymorphic fibers, while that in the supplemented rats, the histological analysis showed an accentuated reduction of those alterations that resulted in an almost inexistence of muscular lesions. Having in mind the obtained results, it can be suggested that the antiinflammatory action of AGPI ?-3 in the rats and for extension in athletes, would be improved if the supplementation was administered daily independently of the training period / Doutorado / Nutrição Experimental e Aplicada à Tecnologia de Alimentos / Doutor em Alimentos e Nutrição

Achieving adequate and appropriate recovery from exercise is essential in ensuring optimal performance during repeated bouts of exercise. The use of various recovery interventions has become popular in an attempt to enhance subsequent performance and accelerate post-exercise recovery. The application of various post-exercise hydrotherapy interventions has become increasingly popular, however, the majority of current recovery practices appear to be based largely on anecdotal evidence as opposed to rigorous scientific research or evidence based findings. Physiologically, various hydrotherapy protocols have been shown to affect the body via fluid shifts (interstitial to intravascular space), changes in blood flow and cardiovascular function, and reductions in oedema. The possible psychological effects of water immersion must also be considered, with athletes commonly reporting reduced sensations of fatigue and soreness following immersion. Current literature suggests both hydrostatic pressure and water temperature to be important factors influencing the success of hydrotherapy. The overall aim of the present thesis was to enhance current knowledge and understanding with regards to the physiological and performance effects of various forms of hydrotherapy, used as a post-exercise recovery intervention. Initially, four cold water immersion interventions were compared to active recovery, performed between two bouts of high intensity cycling in hot environmental conditions. Effectiveness of recovery was determined via performance in a subsequent exercise bout; in addition, core body temperature, lactate, and heart rate were recorded. The remaining studies were designed to investigate the effects of cold water immersion, hot water immersion, contrast water therapy, and passive recovery 4 (control) following exercise-induced fatigue and exercise-induced muscle damage. Rate of recovery was assessed through changes in performance, core body temperature, thigh girths, blood markers, and perceived exertion/soreness. The results of the combined studies indicate cold water immersion to be more effective than active recovery when performed immediately post-exercise between two bouts of high intensity cycling in hot environmental conditions. Additionally, both cold water immersion and contrast water therapy were effective in aiding recovery from exercise-induced fatigue and exercise-induced muscle damage. Performance variables indicated an improved maintenance or return of performance following these recovery protocols. The present studies have provided additional information to the limited knowledge base regarding the effect of post-exercise hydrotherapy interventions, specifically, the effect of such interventions on subsequent athletic performance. In conclusion, cold water immersion and contrast water therapy appear to be superior to hot water immersion, active recovery, and passive recovery following fatiguing and muscle damaging exercise. Functional and physiological recovery was enhanced following the use of these two recovery protocols.

Epidemiological studies consistently report that muscular strains are a primary injury type in rugby union with the majority of the strains occurring to the quadricep and hamstring musculature. Recently it has been suggested that poor eccentric muscular strength is a precursor to hamstring and quadriceps strains during intermittent sports that require rapid acceleration and deceleration. Despite the high incidence of these muscle injuries in Rugby Union there has been little research into the possible mechanisms involved. Thus, the purpose of this study was to measure the physiological and perceptual responses during a simulated Rugby Union laboratory protocol and further, to identify changes in muscle recruitment patterns and muscle strength over time by comparing this protocol to a continuous, constant load protocol covering the same distance. The experimental condition (EXP) required university level players to perform 80 minutes of simulated rugby union play in a laboratory setting (on a walkway of 22m) which was compared to that of a control condition (CON) which involved subjects covering the same distance, at a constant speed of 4.2km.h-1 on a treadmill. Physiological, biophysical and perceptual responses were measured pre-, at half-time and post-protocol. Heart rate was significantly (p<0.01) greater as a result of EXP in comparison to the CON. Electromyography (EMG) of the vastus medialis was significantly (p<0.01) greater during the CON protocol. The EXP condition elicited higher iEMG activity in the hamstring musculature at all time intervals. In addition the iEMG of the semitendinosus decreased significantly (p<0.01) as a result of the EXP protocol. Peak eccentric knee extensors (EXT) (-13.19%) and flexors (FLEX) (-12.81%) torque decreased significantly during the experimental protocol. After passive half-time (236.67 + 56.27Nm (EXT) and 173.89 + 33.3NM (FLEX)) and at the end of the protocol (220.39 + 55.16Nm and 162.89 + 30.66Nm) reduced relative to pre protocol (253.89 + 54.54Nm and 186.83 + 33.3Nm). Peak eccentric knee extensors did not change during the control protocol. „Central‟ and ‟Local” Rating of Perceived Exertion values were significantly (P<0.01) greater during the EXP protocol with an increased incidence of hamstring discomfort and perceived pain (5 out of 10). The EXP protocol resulted in significantly (p<0.01) increased incidence of delayed onset muscle soreness (DOMS). In conclusion, a stop-start laboratory protocol elicited increased heart rate, negatively impacted on muscle activity of the hamstrings, decreased eccentric strength in the lower limb musculature, resulted in increased ratings of „Central‟ and „Local‟ exertion and increased pain perception and increased incidence of DOMS. Thus, a stop-start rugby specific laboratory protocol has a negative impact on performance. Due to the specificity of the protocol being designed to match the demands of competitive match play it is expected that these changes in heart rate, muscle activity and strength, particularly eccentric strength, will impact negativity on performance during rugby match play and increase the likelihood of injury

In this project, the effects of dietary polyphenols on exercise-induced muscle damage and vascular health are examined. Dietary polyphenols exert well-known anti-inflammatory effects; however, how these effects are realized with respect to vascular health and EIMD is relatively unknown. I begin by reviewing the available literature surrounding the impact of three dietary polyphenols (curcumin, catechins, and quercetin) on inflammation associated with EIMD. It is well established that their primary means of anti-inflammation is through alterations of NF-κB and AP-1 transcription activities. Given this, their inclusion into training strategies seems reasonable. Consistent evidence is presented making a case for the anti-inflammatory effects of dietary polyphenols following EIMD. I follow this review up by completing an in-depth study on the consumption of curcumin prior to EIMD. I found curcumin (1000 mg/day) can reduce subjective soreness and decrease inflammation compared to placebo controls. To further understand the effects of dietary polyphenols on health, I investigate the effects of a four-week supplementation period of cocoa (catechins) on vascular. I concluded that atherogenic risk in obese women is reduced after consumption of cocoa. In addition to these experimental projects, I developed two novel methods that can be used to investigate vascular health (EMP concentration) and intracellular protein and mRNA production using flow cytometry.

Thesis (MSc)--University of Stellenbosch, 2007. / ENGLISH ABSTRACT: Human studies on the response of muscle to contusion injury are limited, probably due to the large variability in injury severity and the non-specificity of clinical symptoms reported. To circumvent this problem, several experimental animal models have been designed to study muscle damage and regeneration after contusion injuries. However, the majority of techniques currently used to induce contusion injury are very invasive and therefore not optimal. Furthermore, published studies regarding clinical treatment of such injuries are limited. The main aims of this study were therefore: a) to establish and characterise an in vivo model of non-invasive contusion injury, and b) to assess the effect of pre-injury chronic administration of the antioxidant supplement Oxiprovin™ - a natural grape seed extract (GSE) - on skeletal muscle recovery after experimentallyinduced injury. Two groups of male Wistar rats were subjected to 14 days of oral administration of isovolaemic placebo (sterile isotonic saline) or GSE (20 mg/kg/day) prior to induced contusion. Contusion injury was induced with the mass-drop technique, and recovery parameters assessed for up to 14 days post-injury. Placebotreated rats on average exhibited a 56 % higher creatine kinase (CK) activity when compared to the GSE-treated rats when area under the curve (AUC) was calculated for 14 days post-injury (p < 0.001). In the placebo group, plasma oxygen radical absorbance capacity (ORAC) was unchanged over time, but muscle ORAC was significantly increased by day 7 post-injury (p < 0.001). In the GSE group, a significant decrease in both plasma (p < 0.01) and muscle ORAC (p < 0.001) was evident 4 hr after injury, followed by a significant increase by day 3 (p < 0.05 and p < 0.001 respectively). CD34+ satellite cell (SC) numbers (quiescent and activated) peaked earlier in GSE-treated rats when compared to placebo-treated rats (4 hours vs. day 7 post-injury). Total satellite cell number (CD56+) also peaked earlier in GSE-treated rats than in placebo-treated rats (4 hours vs. 3 days post-injury), while M-cadherin+ SC numbers (quiescent, activated or proliferating) in both treatment groups were significantly increased 4 hours post-injury (p < 0.001), but more so in the placebo group. In GSE-treated rats when compared to placebo-treated rats, newly generated muscle fibres (displaying central nuclei and MHCf +) both appeared (day 3 vs. day 7 post-injury) and peaked in number (day 3 vs. day 7 post-injury; increase from baseline p < 0.001 for both) earlier. The results of this study demonstrate that we have successfully established an in vivo model for non-invasive contusion injury in rats. Furthermore, we have shown that Oxiprovin™: a) increased the ability to scavenge reactive species generated after injury and b) resulted in the activation of satellite cells and formation of newly generated muscle fibres at an earlier time point, thus accelerating the recovery of skeletal muscle after a standardised contusion injury. / AFRIKAANSE OPSOMMING: Eksperimente aangaande die reaksie van spier op kneusings in mense is beperk, waarskynlik as gevolg van die groot verskeidenheid simptome wat mag voorkom en die verskille in die ernstigheid van beserings. Ten einde hierdie problem te oorbrug, is verskeie eksperimentele diermodelle opgestel om kneusings en die herstel van spier daarna te ondersoek. Die tegnieke wat grootendeels vandag gebruik word om kneusings te veroorsaak, maak inbraak op die spier deur die spier te ontbloot voor besering, en is dus nie ideaal nie. Daar is ook nie baie bewyse aangaande die mees geskikte manier om so ‘n besering klinies te behandel nie. Die doel van hierdie studie was dus om: a) ‘n in vivo model van kneusings op te stel en te omskryf, en b) die effek van chroniese toediening van die antioksidant Oxiprovin™ - ‘n natuurlike druifsaad ekstrak (DSE) – op die herstel van skeletspier na ‘n kneusing te ondersoek. Twee groepe manlike Wistar rotte is onderwerp aan mondelikse toediening van isovolemiese plasebo (steriele isotoniese soutoplossing) of DSE (20 mg/kg/dag) vir ‘n tydperk van 14 dae voor kneusing. Kneusing is geïnduseer met die “massdrop” tegniek, en parameters van herstel is ondersoek tot en met 14 dae na besering. Plasebo-behandelde rotte het gemiddeld 56 % hoër kreatien kinase (KK) aktiwiteit in vergelyking met DSE-behandelde rotte (p < 0.001), toe die oppervlak onder die kurwe (OOK) tot en met 14 dae na besering bereken is. Geen verskil oor tyd is in die plasebo groep opgemerk toe plasma suurstof radikaal absorpsie kapasiteit (SRAK) bepaal is nie, maar ‘n betekenisvolle toename in spier SRAK teen dag 7 (p < 0.001) is waargeneem. ‘n Betekenisvolle afname in beide plasma (p < 0.01) en spier (p < 0.001) SRAK van die DSE is teen 4 hr waargeneem, gevolg deur ‘n betekenisvolle toename teen dag 3 na besering (p < 0.05 en p < 0.001 onderskeidelik). Die aantal CD34+ satelliet selle (SS – rustend en geaktiveerd) het beduidend vroeër in die DSE groep gestyg in vergelyking met die plasebo groep (4 uur vs. 7 dae na besering). Die totale aantal SS (CD56+) het ook vroeër in die DSE-behandelde rotte as die plasebobehandelde rotte gestyg (4 uur vs. 3 dae na besering), terwyl die aantal Mcadherin+ SS (rustend, geaktiveerd of prolifererend) betenisvol gestyg het in beide groepe teen 4 uur (p < 0.001) na besering, maar hoër in die plasebo groep was. Die aantal nuutgevormde spiervesels (met sentraal geleë nukleï en MHCf +) het beide vroeër verskyn en gepiek in die DSE-behandelde rotte in vergelyking met die plasebo-behandelde rotte (dag 3 vs. dag 7 na besering). Die resultate van hierdie studie dui aan dat ons instaat was om ‘n in vivo model van nie-indringende kneusing in rotte op te stel. Verder, het ons ook bewys dat Oxiprovin™ toediening die vermoë verleen het om: a) reaktiewe spesies wat na beserings gevorm word, meer doeltreffend te verwyder en b) satelliet selle vroeër te aktiveer en die vorming van nuwe skeletspiervesels te vervroeg, om sodoende die herstel van skeletspier na ‘n gestandardiseerde kneusing vinniger te bewerkstellig.

Graduation date: 2004