Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T13:05:19Z No. of bitstreams: 1 TES_GILMARA_PANDOLFO_ZABOT_PARCIAL.pdf: 628717 bytes, checksum: ac6c7a3620466ffc6fc2346323b1beef (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T13:05:27Z (GMT) No. of bitstreams: 1 TES_GILMARA_PANDOLFO_ZABOT_PARCIAL.pdf: 628717 bytes, checksum: ac6c7a3620466ffc6fc2346323b1beef (MD5) / Made available in DSpace on 2017-06-30T13:05:37Z (GMT). No. of bitstreams: 1 TES_GILMARA_PANDOLFO_ZABOT_PARCIAL.pdf: 628717 bytes, checksum: ac6c7a3620466ffc6fc2346323b1beef (MD5) Previous issue date: 2017-03-15 / Aims: The aim of the present study was to evaluate possible preventative effects of glutamine in an animal model of PH induced by partial portal vein ligation (PPVL). Materials and methods: Twenty four male Wistar rats were divided into four experimental groups: (1) control group (Control) ? rats underwent exploratory laparotomy; (2) control + glutamine group (Control + G) ? rats were subjected to laparotomy and treated intraperitoneally with glutamine; (3) portal hypertension group (PPVL) ? rats were subjected to PPVL; and (4) PPVL+ glutamine group (PPVL + G) ? rats were treated intraperitoneally with glutamine during seven days. Local injuries were determined by evaluating intestinal segments for oxidative stress using lipid peroxidation, the activity of glutathione peroxidase (GPx), eNOS and iNOS after PPVL. Results: Lipid peroxidation of the membrane was increased in the animals subjected to PH (P < 0.01). However, the group that received glutamine for seven days after the PPVL procedure showed levels of lipid peroxidation similar to the control groups (P > 0.05). The activity of the antioxidant enzyme GTx was decreased in the gut of animals subjected to PH when compared with the control group of animals not subjected to PH (P < 0.01). However, the group that received glutamine for seven days after the PPVL showed similar GTx activity to both control groups not subjected to PH (P > 0.05). The mean area of eNOS staining for each of the control groups was similar. The PH group showed the largest area of staining for eNOS. The PPVL + G group had the second highest amount of staining, but the mean value was much lower than that of the PH group (P < 0.01). For iNOS, control (SO) and control + G (SO + G) groups showed similar areas of staining. The PH group contained the largest area of iNOS staining, followed by the PPVL + G group; however, this area was significantly smaller than that of the group that underwent PH without glutamine (P < 0.01). Conclusions: These results demonstrate that pretreatment with glutamine prevents mucosal injury and improves gut recovery after portal hypertension injury in rats. / Objetivos: O objetivo principal do presente estudo foi avaliar a a??o da glutamina em ratos com hipertens?o portal (HP), submetidos ao modelo experimental de ligadura parcial da veia porta (LPVP). Os objetivos secund?rios foram: determinar a lipoperoxida??o no intestino atrav?s da t?cnica de subst?ncias reativas ao ?cido tiobarbit?rico (TBARS); avaliar a atividade de uma enzima antioxidante (glutationa peroxidase) no intestino; avaliar as altera??es histopatol?gicas, consequentes ? HP, no intestino; quantificar a express?o das enzimas ?xido n?trico sintase endotelial (eNOS) e ?xido n?trico sintase induz?vel (iNOS), pela t?cnica de imunoistoqu?mica. Material e M?todos: Ratos machos da ra?a Wistar foram mantidos em caixas pl?sticas, em ciclo de 12 horas claro/escuro, com ?gua e ra??o administradas ad libitum. Foram utilizados Vinte e quatro ratos divididos, de forma randomizada, em quatro grupos experimentais: (1) grupo controle (Controle) ? (Grupo submetido ? simula??o da cirurgia, e administra??o de ve?culo: cloreto de s?dio - NaCl); (2) grupo controle + glutamina (Glutamina) ? os ratos foram submetidos ? simula??o da cirurgia e administra??o da glutamina; (3) Hipertens?o portal (LPVP) ? os ratos foram submetidos ? LPVP e administra??o de ve?culo: NaCl; e (4) hipertens?o portal + glutamina (LPVP + G) - os ratos foram submetidos ? LPVP e administra??o de glutamina. As consequ?ncias da hipertens?o portal, no intestino, foram determinadas por meio da avalia??o dos segmentos de intestino delgado para o estresse oxidativo, atrav?s da lipoperoxida??o, da atividade da enzima glutationa peroxidase, da express?o das enzimas eNOS e iNOS, al?m da an?lise das altera??es histopatol?gicas ap?s a LPVP. Resultados: A lipoperoxida??o da membrana foi mais expressiva no grupo de animais submetidos ? LPVP (P < 0,01). Entretanto, o grupo que recebeu a glutamina, mostrou n?veis de lipoperoxida??o, de forma similar aos grupos controles (P > 0,05). O grupo submetido ? LPVP apresentou mais altera??es da mucosa, quando comparado ao grupo que recebeu a glutamina durante os 7 dias seguintes ? LPVP e tamb?m aos grupos controles, por?m, estes achados n?o obtiveram signific?ncia estat?stica (P > 0,05). A atividade da enzima glutationa peroxidase estava diminu?da no intestino de animais submetidos ? LPVP, quando comparada a encontrada nos grupos controles sem a LPVP (P < 0,01). J? o grupo que recebeu a glutamina, mostrou uma redu??o menor, comparada ao grupo de LPVP sem o amino?cido. Este resultado tamb?m apresentou signific?ncia estat?stica (P < 0,05). Este grupo foi semelhante aos grupos controles (P > 0,05). A m?dia da ?rea, dosada atrav?s do m?todo de imunoistoqu?mica, da express?o da enzima eNOS para os grupos controles, foi similar. O grupo submetido ? LPVP mostrou a maior ?rea de concentra??o. O grupo LPVP + G foi o que teve a segunda maior ?rea, por?m com valores menores do que os encontrados no grupo do evento LPVP (P < 0,01). Para a enzima iNOS, os grupos controles, com e sem a glutamina, mostraram ?reas similares. O grupo da LPVP apresentou a maior ?rea de express?o da enzima, seguido pelo grupo LPVP + G por?m, esta ?rea foi significativamente menor do que a do grupo submetido ? LPVP sem a glutamina (P < 0,01). Conclus?es: Estes resultados demonstram que, o tratamento com glutamina, previne a les?o da mucosa do intestino, ap?s LPVP, em ratos.

Submitted by PPG Biologia Celular e Molecular (bcm@pucrs.br) on 2017-07-18T12:45:18Z No. of bitstreams: 1 FERNANDA_CRISTINA_DE_MESQUITA_TES.pdf: 3705815 bytes, checksum: d4984b596a690199bbc567a00b9a5f63 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-07-28T18:46:03Z (GMT) No. of bitstreams: 1 FERNANDA_CRISTINA_DE_MESQUITA_TES.pdf: 3705815 bytes, checksum: d4984b596a690199bbc567a00b9a5f63 (MD5) / Made available in DSpace on 2017-07-28T18:54:15Z (GMT). No. of bitstreams: 1 FERNANDA_CRISTINA_DE_MESQUITA_TES.pdf: 3705815 bytes, checksum: d4984b596a690199bbc567a00b9a5f63 (MD5) Previous issue date: 2017-03-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Liver fibrosis is the wound healing response to repeated injury of the liver. This process begins with the damage of the parenchymal cells and subsequent inflammation, characterized by the rupture of the hepatic architecture associated to the increase of the expression of the components of the extracellular matrix. The development of hepatic fibrosis is based on the activation of hepatic stellate cells (HSC) that undergo phenotypic changes and are characterized by loss of vitamin A deposition and increased cell proliferation, triggering hepatic microcirculatory dysfunction and fibrogenesis in patients with chronic liver disease (CLD). Liraglutide is a GLP-1 agonist (glucagon-like peptide 1) well established as an antidiabetic drug, but also has anti-inflammatory properties, in addition to the effectiveness for NAFLD (non-alcoholic fatty liver disease). Therefore, the aim of this study was to evaluate the effects of liraglutide on the HSC phenotype and liver microvascular function using diverse pre-clinical models of CLD. The results obtained demonstrate that Liraglutide de-activated human and rat HSC phenotype through a GLP1-Rindependent mechanism. Liraglutide did not affect the HSC viability but decreased cell proliferation. CLD-rats receiving liraglutide exhibited significantly lower portal pressure (-20%) with a consequent reduction in intrahepatic vascular resistance. There was also a marked improvements in hepatic vascular function, fibrosis, HSC phenotype and sinusoidal endothelial phenotype. The anti-fibrotic effects of liraglutide were confirmed in human liver tissue. In conclusion, this study demonstrates for the first time that liraglutide improves hepatic sinusoidal endothelium in clinically relevant experimental models of cirrhosis, which leads to improvement in fibrosis and portal hypertension, and therefore is valid in the treatment of advanced chronic liver disease. / A fibrose hep?tica ? a resposta cicatricial do f?gado ? les?es repetidas. Este processo inicia com o dano das c?lulas parenquimatosas e consecutiva inflama??o, caracterizado pelo rompimento da arquitetura hep?tica associada ao aumento da express?o dos componentes da matriz extracelular. O desenvolvimento da fibrose hep?tica ? baseado na ativa??o das c?lulas hep?ticas estreladas (HSC) que sofrem mudan?as fenot?picas e se caracterizam pela perda do dep?sito de vitamina A e aumento da prolifera??o celular, desencadeando disfun??o microcirculat?ria hep?tica e fibrog?nese nos pacientes com doen?a hep?tica cr?nica (CLD). A liraglutida ? um an?lago do GLP-1 (glucagon-like peptide 1) bem estabelecido como f?rmaco antidiab?tico, mas que tamb?m possui propriedades antinflamat?rias, al?m da efetividade para NAFLD (doen?a hep?tica gordurosa n?o alco?lica). Por essa raz?o, o objetivo deste estudo foi avaliar os efeitos da liraglutida sobre o fen?tipo das HSC e a fun??o microvascular hep?tica utilizando diversos modelos pr?-cl?nicos de CLD. Os resultados obtidos demonstram que a liraglutida desativou o fen?tipo das HSC humanas e de ratos atrav?s de um mecanismo independente do receptor GLP1. A liraglutida n?o afetou a viabilidade das HSC mas diminuiu a prolifera??o celular. Os ratos com CLD que receberam liraglutida apresentaram press?o portal significativamente menor (-20%) com consequente redu??o da resist?ncia vascular intra-hep?tica. Houve tamb?m uma acentuada melhoria na fun??o vascular hep?tica, fibrose, fen?tipo das HSC e fen?tipo endotelial sinusoidal. Os efeitos anti-fibr?ticos da liraglutida tamb?m foram confirmados em tecido hep?tico humano. Como conclus?o, este estudo demonstra pela primeira vez que a liraglutida melhora o endotelio sinusoidal hep?tico em modelos experimentais clinicamente relevantes de cirrose, o que leva a melhora no quadro fibr?tico e na hipertens?o portal e, portanto, pode ser v?lido no tratamento da doen?a hep?tica cr?nica avan?ada.