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Programação da ontogenese renal em um modelo de restrição proteica gestacional = estudos em cultrua de metanefro e in vivo / Renal ontogenesisprogramming by maternal protein restriction : metanephroi culture and in vivo studiesMesquita, Flavia Fernandes 15 August 2018 (has links)
Orientadores: Patricia Aline Boer, Jose Antonio Rocha Gontijo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-15T02:51:36Z (GMT). No. of bitstreams: 1
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Previous issue date: 2010 / Resumo: O desenvolvimento renal é finamente orquestrado por diversos fatores e pequenas modificações neste mecanismo podem resultar no fenótipo de menor número de glomérulos, até agenesia renal. A programação fetal por restrição proteica gestacional está relacionada com a hipertensão arterial manifestada no indivíduo adulto submetido à dieta hipoproteica durante a fase uterina. Estudos descrevem que a "hipertensão programada" pode estar relacionada ao menor número de nefro (30%) encontrado nestes indivíduos. Dados obtidos em animais também confirmam a relação entre dieta materna e número de nefro em animais adultos. Esta tese tem por objetivo determinar desde qual ponto do desenvolvimento a organogênese renal pode ser influenciada pela restrição proteica gestacional, bem como determinar quais adaptações renais, morfológicas e funcionais, o animal sofre em sua vida adulta, relacionadas ao perfil hipertensivo. Ratos Wistar fêmea foram submetidas a dieta hipoproteica durante a gestação, e a prole de machos foi estudada nos experimentos seguintes: A cultura de metanefro mostrou que na idade gestacional de 14.25 dias, o metanefro do embrião desnutrido proteicamente já está "programado" a se ramificar menos do que o controle, gerando menor número de pontos de formação de nefros. A quantificação de glomérulos em embriões de 17.5 dias foi compatível com o resultado do estudo "in vitro". Estudo utilizando PCR em tempo real para avaliar o sistema renina-angiotensina durante a nefrogênese revelou que este sistema não está alterado enquanto intra-utero, no entanto, a expressão de mRNA de renina, angiotensinogênio e receptores de angiotensina II após o nascimento é excessiva quando comparado ao animal controle. Experimentos em animais adultos que sofreram restrição proteica intra-utero revelaram que os receptores de angiotensina II estão regulados negativamente nos rins, comparados aos animais controle. Os animais "programados" nasceram com baixo peso e também apresentaram pressão arterial elevada a partir da 12a semana de vida. A análise da função renal mostrou que a filtração glomerular não está alterada, mesmo com menor número de nefros apresentado neste modelo, sugerindo uma hiperfiltração decorrente da hipertrofia glomerular e podocitária, confirmadas por microscopia eletrônica. Além disso, a fração de excreção de sódio proximal é menor nos animais desnutridos, podendo ser dependente da ação da angiotensina II no transportador Na/K ATPase na membrana basal do túbulo proximal cuja expressão é elevada. O presente estudo demonstrou que a restrição proteica gestacional durante as primeiras semanas de gestação é suficiente para determinar a redução na nefrogênese, levando os rins a adaptações envolvidas no estabelecimento e/ou manutenção da hipertensão arterial / Abstract: The kidney development is a complex mechanism orchestrated by different factors and any alterations at this stage can change the phenotype from a low nephron number to renal agenesis. The maternal protein restriction is related with adult hypertension after low protein diet in utero. Many studies have been demonstrated that "programmed hypertension" can be linked with the low nephron number found in these adults. Animal studies have been found equal relation between maternal diet and nephron number at adult age. Our objective is to determine from each point of development the renal organogenesis can suffer gestational protein restriction influence. Also we look for understand which morphological and functional renal adaptations rats present on adult age, and if these alteration are linked with hypertension. The metanephroi culture shows that at gestational age 14.25, the metanephros from undernourished embryo is already programmed to branch less than control animal, leading to low number of nephron formation sites. The stererological study showed the same result that the "in vitro" study, showing less glomeruli at 17.5 gestational days. RT-PCR for renin-angiotensin system shows that this system is not altered in kidneys from programmed group during intra-uterine life, however renin, angiotensinogen and angiotensin II receptors mRNA expression are up-regulated after birth when compared with control animals. Adult animals from low protein diet in utero showed that angiotensin II receptors are down-regulated in kidneys, when compared with animals that received normal food in utero. These animals also have an up-regulated expression of angiotensin II receptors in adrenals. The "programmed" animals had low birth weight and high arterial pressure from 12th week-age. The renal function study showed that glomerular filtration is not altered, even with low nephron number, what suggests a hyperfiltration, that may be linked with glomerular and podocitary hypertrophy. Indeed, proximal sodium excretion fraction is lower in low birth weight animals, suggesting an angiotensin II action at the basal membrane Na/K ATPase. By western blot, we found that Na/K ATPase protein is up-regulated on kidneys from low protein diet animals. This study demonstrated that early gestational protein restriction is enough to determine the impaired nephrogenesis, leading to renal adaptations to support the establishment of arterial hypertension / Doutorado / Medicina Experimental / Doutor em Fisiopatologia Medica
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Using Multi-Theory Model to Predict Low Salt Intake - Nigerian Adults with HypertensionDokun-Mowete, Christine Adekemi 01 January 2017 (has links)
Hypertension is a chronic non-communicable disease and a major risk factor for cardiovascular diseases, renal malfunction, disability, and premature death. One of the public health recommendations for the management of hypertension is the reduction of sodium/salt intake. There is need to develop and implement new evidence-based theoretical interventions to initiate and sustain behavior change in health education and promotion. Therefore, the quantitative cross-sectional method and design was used to investigate the adequacy of multi-theory model (MTM) constructs for the initiation and the sustenance of low sodium/salt intake behavior in hypertensive Nigerian adults. In addition, the impact of the MTM (initiation) constructs on actual salt/sodium intake was evaluated to validate self-reported behavior. A convenience sample of 149 consenting Nigerian adults with hypertension and of ages 20 to 60 years, self -administered the valid and reliable 39-item MTM instrument. The findings of confirmatory factor analysis showed construct validity of subscales for the initiation and sustenance model. All items loading for the two models were significant, p < 0.001. Multivariate regression analysis revealed 40.6% of the variance in initiating the consumption of low salt diets explained by advantages outweighing disadvantages, behavioral confidence, and changes in physical environment. About 41.8 % of the variance to sustain the intake of low salt diet was explained by emotional transformation, practice for change, and changes in social environment. The results justified the predictive role of MTM and adequacy of its utility to build evidence-based health education programs and interventions to address the health need of people with hypertension and contribute to social change in the country.
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