Aus Voruntersuchungen geht hervor, dass die Expression der organischen Anionentransporter OAT-1 und OAT-3 durch Prostaglandin E2 herabgesetzt wird und dass beide Transporter im ischämisch bedingten akuten Nierenversagen herunter reguliert werden. Da zudem Prostaglandin E2 im iANV vermehrt vorliegt und von Cyclooxygenasen gebildet wird, wurde in dieser Arbeit der Effekt von Indometacin als nicht-selektiver COX-Inhibitor auf die Expression und Funktion von OAT-1 und OAT-3, sowie auf die gesamte Nierenfunktion untersucht. Das ischämisch bedingte akute Nierenversagen wurde bei Ratten durch bilaterales Abklemmen der Aa. renales über 45 Minuten induziert. Indometacin (1mg/kg) wurde hierbei intraperitoneal gegen Ende der Ischämiephase appliziert. Die Gruppeneinteilung erfolgte in Gruppen mit Gefäßabklemmung jeweils mit bzw. ohne Indometacingabe und in Gruppen mit Scheinoperationen. Die Expression von OAT-1 und OAT-3 wurde mithilfe von rt-PCR und Western Blot Verfahren bestimmt, deren Funktion anhand der PAH Nettosekretion ermittelt und die Nierenfunktion mithilfe von PAH- und Inulin Clearance analysiert. Alle Parameter wurde 24h nach renaler Ischämie betrachtet. In Ischämie-Tieren konnte Indometacin die Expression von OAT-1 und OAT-3 und die PAH Nettosekretion wiederherstellen. Zusätzlich vermochte Indometacin auch die Nierenfunktion signifikant gegenüber den Ischämie-Tieren ohne Therapie zu verbessern. So lässt sich zusammenfassend sagen, dass niedrig dosiertes Indometacin eine Herunterregulation von OAT-1 und OAT-3 nach ischämisch bedingtem akuten Nierenversagen verhindert und einen relevanten protektiven Effekt auf die Nierenfunktion zeigt. / The expression of renal organic anion transporters Oat1 and Oat3 is diminished by prostaglandin E(2) (PGE(2)) and both transporters are downregulated after renal ischemia. Because PGE(2) is increased after renal ischemia and is generated by cyclooxygenases (COX), the effect of the COX inhibitor indometacin on expression of Oat1/3 after ischemic acute kidney injury (iAKI) was investigated. iAKI was induced in rats by bilateral clamping of renal arteries for 45 min. Indomethacin (1 mg/kg) was given intraperitoneally as soon as reperfusion started. Sham-treated animals served as controls. Oat1/3 were determined by qPCR and Western blot. PGE(2) in blood and urine was measured by enzyme-linked immunosorbent assay. Glomerular filtration rate and renal plasma flow were determined. All parameters were detected 24 h after ischemia. PAH net secretion, as well as clearance and secretion of PGE(2) were calculated. In clamped animals, indometacin restored expression of Oat1/3, as well as PAH net secretion. Additionally, indometacin substantially improved kidney function as measured by glomerular filtration and PAH clearance. In conclusion, this study indicates that low-dose indometacin applied after ischemia prevents ischemia-induced downregulation of Oat1/3 during reperfusion and has a substantial protective effect on kidney function after iAKI. In accordance to the decreased PAH net secretion, renal excretion of an endogenous organic anion (PGE(2)) is also impaired after ischemia and reperfusion

Universiẗat, Diss.--Münster, 1999.

nÃo hà / Esse estudo tem por finalidade avaliar os efeitos de inibidores seletivos da COX (cetorolaco e celecoxibe) e de inibidores nÃo seletivos (indometacina) da COX sobre o transporte ileal de Ãgua e eletrÃlitos em ratos anestesiados. TambÃm se propÃe a avaliar as alteraÃÃes vilo/cripta do Ãleo de ratos tratados com inibidores seletivos e nÃo seletivos da COX-1 e 2 (cetorolaco-inibidor especÃfico da COX-1 na dose de 3mg/Kg, celecoxibe-inibidor especÃfico da COX-2 e indometacina-inibidor nÃo seletivo da COX). Os animais foram tratados per os durante trÃs dias consecutivos com uma das seguintes substÃncias: cetorolaco (3mg/Kg), celecoxibe (10mg/Kg), indometacina (5mg/Kg), cetorolaco + celecoxibe, salina 0,9% ou tampÃo fosfato. Todos os AINES aqui utilizados foram diluÃdos em soluÃÃo salina (Nacl a 0,9%) exceto a indometacina que foi diluÃda em soluÃÃo tampÃo fosfato. ApÃs jejum de 24 horas com livre acesso à Ãgua, os animais foram anestesiados com Uretana (1,2mg /kg corporal, i.p). A seguir realizou-se laparotomia mediana para isolamento do segmento a ser perfundido. CÃnulas foram introduzidas nas extremidades proximal e distal do segmento mediante criaÃÃo de fÃstulas. O segmento isolado e as cÃnulas formaram o circuito que foi perfundido. Para a perfusÃo foi utilizada soluÃÃo modificada de Ringer e FenolsulftaleÃna 50mg/L como marcador nÃo absorvÃvel. O perfusato foi coletado em tubos de ensaio apÃs 40min (03 amostras). TambÃm foram obtidas 3 (trÃs) amostras no inÃcio e no final (03 amostras) do experimento, para determinaÃÃo dos parÃmetros controle. Foram determinadas as diferenÃas entre as amostras controle e as coletas do perfusato quanto aos valores das concentraÃÃes de sÃdio, potÃssio e cloreto (mmol/L). Ao final do experimento, os animais foram sacrificados e o segmento ileal perfundido retirado, sendo imediatamente pesado, depois retirados anÃis distais de aproximadamente 0,5 cm para o histopatolÃgico. Nova mediÃÃo de peso desse segmento foi realizada apÃs o mesmo ser mantido em estufa a 100oC por 48h, de modo a permitir a correÃÃo dos parÃmetros funcionais. A administraÃÃo de cetorolaco aos animais promoveu secreÃÃo ileal de Ãgua, de sÃdio, cloreto e potÃssio. Por outro lado, o tratamento com celecoxib, sozinho ou em associaÃÃo com cetorolaco, bem como o tratamento com indometacina nÃo desencadearam alteraÃÃes significativas na secreÃÃo de Ãgua, sÃdio, cloro e potÃssio, quando comparado com os grupos controles. Em relaÃÃo as alteraÃÃes morfomÃtricas, os tratamentos com celecoxibe sozinho ou em associaÃÃo com cetorolaco, promoveram um aumento da relaÃÃo vilo/cripta. Por outro lado, a administraÃÃo de cetorolaco aos animais nÃo modificou a relaÃÃo vilo/cripta quando comparado com o controle. Por outro lado, no tratamento com indometacina, a administraÃÃo de indometacina apresentou uma diminuiÃÃo na relaÃÃo vilo/cripta, quando comparado com o controle. Baseado nestes dados podemos concluir, que a inibiÃÃo da COX-1 pelo cetorolaco, mas nÃo a inibiÃÃo da COX-2 pelo celecoxib, desencadeia uma alteraÃÃo funcional na secreÃÃo de Ãgua e eletrÃlitos no Ãleo, pois nÃo houve lesÃo do epitÃlio na anÃlise histolÃgica do intestino de ratos tratados com a cetorolaco. / The aim of this study was to evaluate the effects of selective and non-selective COX inhibitors on water and electrolyte transport and the villous/crypt ratio in the ileum of anesthetized rats. Thirty-six animals distributed in 6 groups were treated with 3mg/Kg ketorolac (a selective COX-1 inhibitor), 10mg/Kg celecoxib (a selective COX-2 inhibitor), 5mg/Kg indometacin (a non-selective COX inhibitor),ketorolac+celecoxib, 0.9% saline solution or phosphate buffer for 3 consecutive days. Ketorolac and celecoxib were diluted in 0.9% saline solution, while indometacin was diluted in phosphate buffer. Following 24 hours of fasting with access to water ad libitum, the animals were anesthetized with 1.2mg/Kg urethane i.p. and submitted to median laparotomy to isolate an ileal segment for perfusion. Cannulae were introduced through surgically created fistulas in the proximal and distal extremities of the segment. Perfusion was performed with modified Ringer solution containing 50mg/L phenolsulfonphthalein (a non-absorbable marker). After 40 minutes, 3 samples of perfusate were collected. In addition, 3 control samples were collected at baseline and by the end of the experiment for comparison of sodium, potassium and chloride concentrations (mmol/L). Finally the animals were euthanized, the extremities of the perfused segment were cut off (5-mm rings) for histopathological examination and the segment was weighed. After 48 hours of storage at 100oC, the segment was weighed again in order to correct the functional parameters. The administration of ketorolac promoted secretion of ileal water, sodium, potassium and chlorine. However, treatment with celecoxib alone or with ketorolac, and indomethacin treatment did not induce significant changes in the secretion of water, sodium, potassium and chlorine, when compared with control groups. In the histological evaluation, treatment with celecoxib alone or in combination with ketorolac, induced an increase in villous / crypt ration. On the other hand, ketorolac administration did not change the villous / crypt ration when we compared with the control. Indomethacin treatment induced a decrease in villous / crypt ration compared with the control. Based on these data we can conclude that inhibition of COX-1 by ketorolac, but not COX-2 inhibition by celecoxib, induced a functional change in the ileal water and electrolytes secretion, since there was not epithelial damage in the histological analysis of intestine of rats treated with ketorolac.

<p>Patients with peritonitis or malignant obstructive jaundice (HPB⁺) have an increased morbidity and mortality due to sepsis. An altered cell-mediated immunity in the intestinal mucosa might promote gut barrier failure, increased endotoxin and cytokine release and bacterial translocation (BT) in these conditions. A clinically relevant rat model of polymicrobial peritonitis induced sepsis by cecal ligation and puncture (CLP) was used. Septic animals demonstrated a superficial injury in the small intestinal mucosa, and a significant reduction in T lymphocytes in the villi, as well as increased number of macrophages in the villi and in the MLNs as compared to sham. CLP caused increased concentration of TNF-α and IL-6 in ascitic fluid. CLP + the immunomodulator Linomide decreased the TNF-α level, reduced mucosal damage and attenuated the changes in T lymphocytes and macrophages observed following CLP. CLP + selective cyclooxygenase (COX)-2 inhibitor (SC-236) or nonselective COX inhibitor (indometacin) decreased the amount of macrophages in the mucosa and the MLNs compared to untreated CLP. CLP + indometacin decreased T lymphocytes in the villi and MLNs. SC-236 + CLP reduced mucosal injury and cytokine release as compared to indometacin. An increased rate of apoptosis in both the mucosa and MLNs was seen following CLP; COX inhibitors enhanced this phenomenon in the MLNs.</p><p>BT occurred infrequently in patients with acute peritonitis and in HPB⁺ there was no evidence of BT. Peritonitis and HPB⁺causes significant inflammatory cellular reactions as increased endotoxin and cytokine plasma levels and an altered immune cell distribution in MLNs, in HPB⁺a high rate of apoptosis in MLNs was observed. </p><p>An altered pattern of immunocompetent cells within the mucosa and in MLNs was found in experimental and clinical peritonitis as in HPB⁺.Lymphocyte depletion may be a result of increased apoptosis, which could reduce the ability of septic or jaundice patients to eradicate infection.</p>

Patients with peritonitis or malignant obstructive jaundice (HPB+) have an increased morbidity and mortality due to sepsis. An altered cell-mediated immunity in the intestinal mucosa might promote gut barrier failure, increased endotoxin and cytokine release and bacterial translocation (BT) in these conditions. A clinically relevant rat model of polymicrobial peritonitis induced sepsis by cecal ligation and puncture (CLP) was used. Septic animals demonstrated a superficial injury in the small intestinal mucosa, and a significant reduction in T lymphocytes in the villi, as well as increased number of macrophages in the villi and in the MLNs as compared to sham. CLP caused increased concentration of TNF-α and IL-6 in ascitic fluid. CLP + the immunomodulator Linomide decreased the TNF-α level, reduced mucosal damage and attenuated the changes in T lymphocytes and macrophages observed following CLP. CLP + selective cyclooxygenase (COX)-2 inhibitor (SC-236) or nonselective COX inhibitor (indometacin) decreased the amount of macrophages in the mucosa and the MLNs compared to untreated CLP. CLP + indometacin decreased T lymphocytes in the villi and MLNs. SC-236 + CLP reduced mucosal injury and cytokine release as compared to indometacin. An increased rate of apoptosis in both the mucosa and MLNs was seen following CLP; COX inhibitors enhanced this phenomenon in the MLNs. BT occurred infrequently in patients with acute peritonitis and in HPB+ there was no evidence of BT. Peritonitis and HPB+ causes significant inflammatory cellular reactions as increased endotoxin and cytokine plasma levels and an altered immune cell distribution in MLNs, in HPB+ a high rate of apoptosis in MLNs was observed. An altered pattern of immunocompetent cells within the mucosa and in MLNs was found in experimental and clinical peritonitis as in HPB+. Lymphocyte depletion may be a result of increased apoptosis, which could reduce the ability of septic or jaundice patients to eradicate infection.