Bibliography: leaves 175-206. / 206 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Evaluates the potential therapeutic application of peptide growth factors, in particular epidermal growth factor, in the treatment of colonic ulcerative conditions. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1993?

Orientador: Denise Vaz de Macedo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-08T20:10:55Z (GMT). No. of bitstreams: 1 Hohl_Rodrigo_D.pdf: 822844 bytes, checksum: fd38d4c98d17c89e25fcfd09540ba103 (MD5) Previous issue date: 2007 / Resumo: O empirismo do treinamento pode levar a um desequilíbrio entre estímulo da atividade motora e tempo de recuperação do esforço. Como conseqüência o atleta pode experimentar um estado agudo de fadiga e queda de desempenho denominado de overreaching, revertido em poucos dias. A persistência desta situação de desequilíbrio pode levar a um quadro crônico de sensação de fadiga acompanhado de queda de desempenho denominado de síndrome do overtraining (OTS), que pode durar semanas ou meses. O objetivo deste trabalho foi padronizar um protocolo controlado e reprodutível de treinamento em ratos que contivesse um período de desequilíbrio entre o estímulo do exercício e o tempo de recuperação que gerasse queda de desempenho. Há duas formas de exercício em ratos amplamente utilizadas na literatura: a natação e a corrida em esteira. Os primeiros dois capítulos deste trabalho descrevem a padronização de um teste de desempenho em natação, reprodutível ao longo do crescimento animal, para ser utilizado em estudos longitudinais. Para isso, precisávamos considerar o empuxo sofrido pelo animal no meio líquido e validamos (Capítulo I) um aparato de medição de volume para animais vivos e conscientes (AMV). No capítulo II apresentamos os dados da comparação da reprodutibilidade de dois testes de desempenho até a exaustão na natação durante os cinco primeiros meses de vida dos ratos. Um teste com adição de cargas ajustadas de acordo com o porcentual da massa corporal (MC) e outro com cargas constantes (CC). Utilizando o AMV constatamos que a densidade dos animais não variava e, como conseqüência, o teste MC diminuía o tempo de exaustão conforme os ratos aumentavam a massa durante o crescimento, enquanto o teste CC mantinha o tempo de exaustão ao longo do tempo. Paralelamente, iniciamos os estudos com exercício em esteira. No Capítulo III apresentamos um protocolo de 11 semanas, onde o desequilíbrio entre exercício e recuperação foi determinado pelo aumento das sessões diárias nas três últimas semanas em 2, 3 e 4 vezes, com diminuição no tempo de recuperação entre elas. Selecionamos no final desse treinamento dois grupos de ratos, aqueles que apresentaram baixo desempenho (BD) e aqueles que apresentaram aumento ou manutenção do desempenho (AD). Embora ambos os grupos tenham apresentado uma diminuição da massa corporal durante o aumento da freqüência de treinamento, o grupo BD precisou de uma semana a mais de repouso para voltar a aumentar a massa, sem modificar o desempenho. No Capítulo IV comparamos quatro grupos de ratos obtidos desse protocolo (Controle (CO), Treinados (T), BD e AD) em análises no sangue (glutamina, glutamato, alanina e hemograma) e músculo (citrato sintase (CS), lactato desidrogenase e glicogênio). Comparando BD com T e AD observamos: (1) diminuição da concentração plasmática de glutamina e aumento na de glutamato, com valores semelhantes aos do grupo CO; (2) diminuição da capacidade oxidativa (CS) e manutenção dos estoques de glicogênio; (3) leucocitose. Em vista das diferenças encontrada entre os grupos BD e AD, concluímos que o protocolo de treinamento de indução de overreaching representa uma ferramenta metodológica importante, que pode auxiliar no desvendamento dos mecanismos causadores da queda de desempenho nos estados de overreaching/OTS / Abstract: The empirical training can lead to an imbalance between the motor activity stress and recovery. As consequence, the athlete can try an acute state of fatigue and performance decrement called overreaching, reverted in a few days. This continuous unbalance can lead to a chronic fatigue state called as overtraining syndrome (OTS), that may last weeks or months. Our goal was to standardize a controlled and reproducible training protocol in rats that contained an unbalance period between exercise stress and recovery with performance decrement. Two forms of exercise is widely used for rats training in literature: swimming and treadmill running. Chapters I and II describe an adequate standardization for workload in swimming tests when applied to longitudinal studies with sedentary rats. Therefore, considering the rats' buoyance, we validate (Chapter I) an apparatus for measuring conscientious living rat body volume (AMV). In chapter II, we evaluated two types of swimming tests with overload in sedentary rats: one with the load adjusted according to percentage of body weight (BW) and another one with constant load (CL) over time. Through the AMV, we found that the rats' density did not vary significantly, as consequence, MC test showed performance decrement as the rats had their mass increased, while CC test maintained performance along rats growth. In time, we initiate the studies with treadmill exercise. In Chapter III, we present an eleven weeks training protocol where the unbalance between exercise stress and recovery was determined by the increase of the daily sessions in 2, 3 and 4 times in the last three weeks, reducing the recovery time between sessions. We selected two groups of rats in the end of the training protocol, those that presented low performance (BD) and those that presented performance increase or maintenance (AD). Although both groups (AD and BD) showed corporal mass reduction during the increase of the daily frequency, BD group return to increase the mass one week later than AD group, without modifying the performance. In Chapter IV, we compare four groups of rats after the eleven weeks training protocol (Control (CO), Trained (T), AD and BD) in blood (glutamine, glutamate, alanine and hematological variables) and muscle analyses (citrate synthase (CS), lactate dehydrogenase and glycogen). Comparing BD with AD and T groups, we observe: (1) reduction of the glutamine plasma concentration and increase of glutamate, with similar CO values; (2) reduction of the oxidative capacity (CS) and maintenance of the glycogen stores; (3) leucocitosys. We conclude that the training protocol induces the rats to overreaching and it represents a relevant methodological tool in overreaching / OTS metabolical mechanisms research envolved in performance decrement / Doutorado / Fisiologia / Doutor em Biologia Funcional e Molecular

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Melatonin is a product of the pineal gland and is postulated to play an antigonadotropic role in the reproductive system of mammals. The reproductive system of non-seasonally breeding mammals is believed to be not as responsive to melatonin treatment as that of seasonally breeding mammals. Recently, there has been increasing support from in vivo and in vitro studies, for the hypothesis that melatonin has negative effects on sperm physiology, especially on sperm motility. High and/or low seminal concentrations of melatonin have been associated with abnormalities in human sperm motility and concentration. In this study, I examined the effects of melatonin on the testis, epididymis and sperm physiology, using in vivo and in vitro experiments, in a non-seasonally breeding mammal. Treatment, in vivo, with exogenous melatonin for six weeks did not inhibit testosterone production or spermatogenesis, nor did it affect the mass of the testes and epididymides at dissection, the concentration the morphology of speimatozoa. However, melatonin in vivo had a small, but significant negative effect on sperm motility and sperm motility index. In vitro incubation of spermatozoa Fith melatonin reduced the percentage (%) of forward progressive movement (fpm), increased the % reduction in fpm, reduced the vigor or quality of sperm motility, reduced the sperm motility index, and delayed and/or prolonged the transition of one pattern of sperm motility to the subsequent patterns. Melatonin increased the pH of the culture medium, and the increased pH, and the ethanol utilized as a solvent for melatonin, both negatively affected all the sperm motility parameters that were assessed in my study. The effects of ethanol increased with time, and the effects of pH increased with both time and increasing pH. Melatonin in vitro did not inhibit capacitation and the acrosome reaction, but it delayed the onset and the progression of capacitation and the acrosome reaction. These results suggest that while melatonin did not inhibit spermatogenesis in the Wistar rat, it may influence sperm motility. Therefore, the presence of high concentrations of melatonin in the reproductive fluids may inhibit sperm motility. With further detailed research, melatonin may have a potential use as a contraceptive drug.

Diabetes is a serious condition that affects all the body’s systems including kidneys, heart, eyes and limbs. This alone makes type II diabetes a life threatening disease; an expensive disease and economic burden that many individuals struggle to cope with.The rapid growth type II diabetes in South Africa is associated with the change of life style, and environmental factors brought by westernized way of life living in rural areas. Despite the technical advances in diagnosis and therapy of diabetes many people still use alternative forms of therapy due to the cost, traditional reasons and religion. Some of the people use the conventional medication together with the alternative therapy without informing their doctor and knowing the pathological changes. The aim of the study was to investigate pathological changes in male Wistar rats after co-treatment of type II diabetes with metformin and Sutherlandia frutescens and the possible synergistic and antagonistic effects. The thirty five rats were divided into five groups, seven in each group. There were two control groups and three test groups. Only the first control group was on a low fat diet (normal rat pellets) and second control group and test groups were on a high fat diet which induces obesity, insulin resistance and leads a typical prediabetic state for 12 weeks (Buettner et al., 2006). After 11.5 weeks medication was administered by oral gavaging to the test groups for 4 weeks and control groups received water. Blood was collected for determination of glucose, insulin, lipid profile and the concentrations of the liver enzymes. Pancreas, liver and kidney tissue were removed and used for histology. Urine was collected from the bladder for creatinine analyses. The plant + metformin group co-treatment was better in managing hyperglycemia, liver damages were minimal and also weight control was better when compared to metformin alone.

During pregnancy, body fat stores increase in part to subsidize the high energy cost of lactation. One effect of exercise, on the other hand, is to lower percent body fat. The effect of exercise during pregnancy and lactation on body fat, and on body composition in general, is not well documented. There is also a paucity of data on the effect of exercise during these physiological states on food intake and body weight. If exercise during pregnancy decreases body fat stores, would lactation performance subsequently be compromised? This study was designed to determine the effect of moderately strenuous aerobic exercise, during rat pregnancy and lactation, on food intake, body weight, body composition and lactation performance. Virgin female Sprague-Dawley rats were divided into exercised (n=40) and sedentary (n=40) groups. Exercising rats were trained over three weeks to run on a treadmill at 30 m/min, 2 hours/day, 5 days/week. Within each group, two subgroups were then mated and three subgroups remained as virgin age controls (n=8 per subgroup). Of the mated subgroups, one was terminated within 24 hours of parturition and the other on day 14 of lactation. Subgroups of virgin sedentary and exercising controls were terminated at times corresponding to each of mating, parturition and day 14 of lactation of mated animals. Carcasses were assayed for fat, water, ash and protein. Ad libitum food intake and body weight were monitored throughout the study, as was the weight gain of pups of lactating dams. MANOVA showed the effect of activity to be significant on food intake at week three of training and during the pregnancy period (p<0.00l) and at week one (p<0.0l) and two (p<0.05) of lactation. The effect of activity was highly significant (p<0.00l) on body weight from week three of training and throughout the pregnancy and lactation periods, as well as on the percent fat, water and ash of the rat carcasses. Post hoc multimean comparisons (Scheffe) at the p<0.05 level revealed that exercise resulted in a significant increase in the food intake of virgin rats, and nonsignificant increases in the food intake of pregnant and lactating rats. Body weights of virgin, pregnant and lactating exercising rats were significantly greater than their respective sedentary controls. Despite their heavier body weights and greater food intake, the estimated carcass energy content of exercising animals was lower than that of sedentary animals. This finding was reflected in the carcass composition whereby exercising rats, whether virgin, pregnant or lactating, contained consistently less fat and more water than sedentary controls. At parturition, pregnant animals contained significantly less fat, more water and more ash than sedentary pregnant controls. After 14 days of lactation, there were no significant differences in carcass composition between exercising and sedentary dams. However, lactating rats, whether exercising or sedentary, catabolized approximately 50 percent of the body fat present at parturition. Pup weight gains were not significantly different between exercising and sedentary dams. From these findings it was concluded that the effect of exercise during pregnancy and lactation on food intake, body weight and body composition was comparable to its effect in non-gravid rats. Moderately strenuous exercise during pregnancy prevented the increase in body fat deposition normally present at this time. Despite these depleted fat stores, the energy supplied by the mobilization of the remaining fat and the increase in food intake was adequate to support normal pup growth. / Land and Food Systems, Faculty of / Graduate

In the present study, the effects of clomiphene citrate (CC) on ovulation, ovarian growth and ovarian steroidogenesis were examined. Ovulation in rats in response to PMSG was completely blocked by administration of three daily treatments of 1.0 mg CC/rat, but was restored by administration of hCG as a preovulatory LH surge substitute. When the number of treatment days was reduced to two days, 1.0 mg of CC enhanced ovulation in response to PMSG, whereas treatment for one day with the same dose of CC did not affect ovulation. The effects of CC on ovulation appear to be dose-dependent. The effects of CC on ovarian growth were similar to the effects of CC on ovulation. The ovarian growth induced by PMSG was inhibited by high doses of CC, while a lower dose had no effect. The inhibition of ovarian growth in terms of ovarian weight by a high dose of CC was restored by hCG given as a preovulatory LH surge. Treatment duration with CC appears to have an important influence on ovarian growth. Three daily treatments with high doses of CC significantly inhibited ovarian growth. However, when the number of treatment days was reduced from three to two, the opposite results were obtained in that CC significantly stimulated ovarian growth. The effects of CC on ovarian steroidogenesis in response to PMSG were dose-dependent. A higher dose of CC significantly stimulated estradiol-17β biosynthesis. Clomiphene citrate did not show any inhibitory effects on progesterone production. Progesterone production was stimulated by hCG in CC treated rats. Lower doses of CC stimulated progesterone and androgen production. Further studies on this are necessary. Histological examination of the ovary revealed that CC selectively inhibited the development of nondominant follicles. The dominant follicles were unaffected as for they were able to develop to the mature stage. These results suggest that the effects of CC on ovulation, ovarian growth and ovarian steroidogenesis are dose-dependent and affected by treatment duration. Clomiphene citrate is assumed to exert its action via a gonadotropic mechanism. / Medicine, Faculty of / Obstetrics and Gynaecology, Department of / Graduate

The cAMP-second messenger hypothesis for β-adrenoceptor-induced relaxation of uterine smooth muscle was tested in high-K+ depolarized rat uterus. At 10⁻⁸ M concentration, Isoproterenol, a β -adrenergic agonist, could cause relaxation of the depolarized uterus without Increasing tissue cAMP levels. Further, although increases in cAMP levels were associated, in some cases, with -isoproterenol (10⁻⁸ M or 10⁻⁴ M)-Induced relaxation, there was no quantitative correlation between the Increases in cAMP and relaxation. Pretreatment of the tissue with a phosphodiesterase Inhibitor, RO 20-1724 (10⁻⁴ M), did not potentiate the relaxation response to Isoproterenol. These results suggested that there Is no simple cause and effect relationship between β -adrenoceptor-Induced Increases in cAMP levels and relaxation in uterine smooth muscle. The dissociation between cAMP and relaxation found ln the present study was also extended to cGMP, since no changes in cGMP levels were observed with isoproterenol-induced relaxation. It is generally accepted that the ionic environment of the cell affects the cellular responses of the tissue. It was demonstrated that hlgh-K*" depolarization of uterine smooth muscle caused an impairment of the ability of isoproterenol to induce cAMP accumulation. This was found to be related to Increased Ca++-Influx known to occur during depolarization. This Is because pretreatment of the tissue with 10⁻⁵M D-600, an Inhibitor of Ca++-lnflux, restored the stimulation of cAMP by Isoproterenol ln the depolarized muscle to a level similar to that observed ln non-depolarized muscle. Furthermore, there was an Inverse relationship between [ca++] ex in the depolarizing medium (range 0.9 to 7.2 mM) and increases in cAMP produced by isoproterenol (10⁻⁴ M). It was also found that exposure of the rat uterus to a Ca++-deficient solution (Ca++-free with 0.2 mM EGTA) accentuated the Increase of tissue cAMP content produced by isoproterenol (10⁻⁸ M). The studies on ionic interactions demonstrated that the presence of Na+(80 mM) or high Mg++(2.5 mM) in the depolarizing medium could overcome the blockade of lsoproterenol-induced increases in cAMP levels by high-K+ depolarization. The studies on the mechanism of this effect of Na+ on the cAMP response revealed that Na+ exerted this effect probably by reducing the Increase In Ca++-influx occurring during depolarization. A similar type of interaction between Mg++ and Ca++ was also observed. These studies have pointed out a possible regulatory role of Ca++ in isoproterenol-lnduced Increases in cAMP levels in uterine smooth muscle. Since it was also demonstrated that cAMP Is not an obligatory requirement In order for Isoproterenol to produce relaxation, these data have raised the question as to whether the Increases ln cAMP produced by β-adrenoceptor stimulation Is an event secondary to the changes in Ca++ movements produced by the agonist. The electrophysiological studies showed that isoproterenol (10 M) could inhibit spontaneous contractility of the rat uterus without causing hyperpolarlzation. In hlgh-K+ depolarized muscle, Isoproterenol (10⁻⁶M) produced relaxation without any change in membrane potential. These data suggested that hyperpolarlzation of cell membranes is not a prerequisite for β-adrenoceptor-med-lated relaxation of uterine smooth muscle. / Pharmaceutical Sciences, Faculty of / Graduate

No description available.

No description available.