Interações entre a ingestão alta de sódio e os peptídeos urodilatina e uroguanilina na função renal de ratos

• Ano de defesa: 2013
• Autor(a) principal: Jorge, Antonio Rafael Coelho
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Fisiologia; Rim; Nefrologia
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/15729

The high sodium intake in the diet has increased considerably in recent decades, promoting the development of several chronic diseases such as hypertension, stroke and coronary heart disea se. Peptides such as urodilatin (UD) and uroguanylin (UGN) have been implicated in the regulation of salt and water homeostasis. However, the regulatory mechanisms are not well understood, as well as their interactions on ren al function. The aim of this work is to study the main effects of the peptides UD and UGN in kidneys of rats subjected to high NaCl intake. The effects were examined using rats for 10 days kept in metabolic cages. The control group received distilled water only, whereas the treated group received 2% solution of NaCl. Kidney function was assessed by perfusion of the isolated rat kidney. Data were compared using Student's t test and ANOVA with significance level of 5%. The UD promoted reduction of perfusion p ressure, renal vascular resistance and urine flow was also observed increased excretion of sodium and chloride, with changes most prominent at the distal level. However, after treatment with salt UD effects were not seen, there was an increase in transport of sodium and chloride to the proximal most pronounced. The effects of UGN were also evaluated in the presence of salt, which was observed to increase perfusion pressure, urine flow and glomerular filtration rate, followed by an increase in the excretion of sodium and chloride, especially at the proximal tubule. The results also showed increased expression of mRNA GC - C receptor and a slight reduction in the expression of GC - A in rats treated with salt. After an increased intake of salt, physiological pathw ays are activated well regulated in order to eliminate excess sodium. The UGN seems to be the primary hormone involved in this pathway, but the UD also have interests in this process. The GC - C receptor is directly involved in the regulation of these physio logical processe.