RESUMO
OBJECTIVE: To evaluate the anti-inflammatory effect of α,ß-amyrin, a pentacyclic triterpenoid from Protium heptaphyllum, on cerulein-induced acute pancreatitis in mice. METHODS: Acute pancreatitis was induced in Swiss mice by five intraperitoneal injections of cerulein (50 µg/kg), at 1 h intervals. Mice received α,ß-amyrin (10, 30 and 100 mg/kg), thalidomide (200 mg/kg), or vehicle (3% Tween 80) orally 1 h before and 12 h after the cerulein challenge. The severity of pancreatitis was evaluated 24 h after cerulein by assessing serum pro-inflammatory cytokines and amylase activity, pancreatic myeloperoxidase (MPO), and thiobarbituric acid-reactive substances (TBARS), as well as by histology. RESULTS: α,ß-Amyrin and thalidomide significantly attenuated the cerulein-induced increase in tumor necrosis factor (TNF)-α, interleukin-6, lipase, amylase, MPO, and TBARS. Moreover, α,ß-amyrin greatly suppressed the pancreatic edema, inflammatory cell infiltration, acinar cell necrosis, and expressions of TNFα and inducible nitric oxide synthase. CONCLUSIONS: α,ß-Amyrin ameliorates cerulein-induced acute pancreatitis by acting as an anti-inflammatory and antioxidant agent.
Assuntos
Anti-Inflamatórios/uso terapêutico , Burseraceae/química , Ceruletídeo/efeitos adversos , Ácido Oleanólico/análogos & derivados , Pancreatite/induzido quimicamente , Pancreatite/tratamento farmacológico , Amilases/sangue , Animais , Anti-Inflamatórios/química , Modelos Animais de Doenças , Imunossupressores/uso terapêutico , Interleucina-6/sangue , Masculino , Camundongos , Óxido Nítrico Sintase Tipo II/metabolismo , Ácido Oleanólico/química , Ácido Oleanólico/uso terapêutico , Pancreatite/patologia , Peroxidase/metabolismo , Distribuição Aleatória , Talidomida/uso terapêutico , Fator de Necrose Tumoral alfa/sangueRESUMO
Pancreatitis is a disease with high morbidity and mortality. In vitro experiments on pancreatic acini showed that supramaximal but not submaximal cholecystokinin (CCK) stimulation induces effects in the acinar cell that can be correlated with acinar morphological changes observed in the in vivo experimental model of cerulein-induced pancreatitis. The GTPase Rac1 was previously reported to be involved in CCK-evoked amylase release from pancreatic acinar cells. Here, we demonstrate that pretreatment with the Rac1 inhibitor NSC23766 (100 microM, 2 h) effectively blocked Rac1 translocation and activation in CCK-stimulated pancreatic acini, without affecting activation of its closely related GTPase, RhoA. This specific Rac1 inhibition decreased supramaximal (10 nM) CCK-stimulated acinar amylase release (27.% reduction), which seems to be connected to the reduction observed in serum amylase (46.6% reduction) and lipase levels (46.1% reduction) from cerulein-treated mice receiving NSC23766 (100 nmol h(-1)). The lack of Rac1 activation also reduced formation of reactive oxygen species (ROS; 20.8% reduction) and lactate dehydrogenase release (LDH; 24.3% reduction), but did not alter calcium signaling or trypsinogen activation in 10 nM CCK-stimulated acini. In the in vivo model, the cerulein-treated mice receiving NSC23766 also presented a decrease in both pancreatic and lung histopathological scores (reduction in oedema, 32.4 and 66.4%; haemorrhage, 48.3 and 60.2%; and leukocyte infiltrate, 53.5 and 43.6%, respectively; reduction in pancreatic necrosis, 65.6%) and inflammatory parameters [reduction in myeloperoxidase, 52.2 and 38.9%; nuclear factor kappaB (p65), 61.3 and 48.6%; and nuclear factor kappaB (p50), 46.9 and 44.9%, respectively], together with lower serum levels for inflammatory (TNF-alpha, 40.4% reduction) and cellular damage metabolites (LDH, 52.7% reduction). Collectively, these results suggest that pharmacological Rac1 inhibition ameliorates the severity of pancreatitis and pancreatitis-associated lung injury through the reduction of pancreatic acinar damage induced by pathological digestive enzyme secretion and overproduction of ROS.
Assuntos
Pneumopatias/metabolismo , Pneumopatias/patologia , Neuropeptídeos/antagonistas & inibidores , Pancreatite/metabolismo , Pancreatite/patologia , Índice de Gravidade de Doença , Proteínas rac de Ligação ao GTP/antagonistas & inibidores , Aminoquinolinas/farmacologia , Amilases/metabolismo , Animais , Cálcio/metabolismo , Membrana Celular/metabolismo , Ceruletídeo/efeitos adversos , Ceruletídeo/farmacologia , Colagogos e Coleréticos/efeitos adversos , Colagogos e Coleréticos/farmacologia , Colecistocinina/efeitos adversos , Colecistocinina/análogos & derivados , Colecistocinina/farmacologia , Citosol/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Pneumopatias/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuropeptídeos/efeitos dos fármacos , Pancreatite/induzido quimicamente , Pirimidinas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Proteínas rac de Ligação ao GTP/efeitos dos fármacos , Proteínas rac1 de Ligação ao GTPRESUMO
Purpose: The pancreatic capillary blood flow (PCBF) was studied to determine its alterations during caerulein-induced pancreatitis in rats. Methods: Twenty rats were divided in groups: control and caerulein. A laser-Doppler flowmeter to measure PCBF continuously was used. Blood pressure (BP) and heart rate (HR) were monitored. Serum biochemistry analyses were determined. Histopathological study was performed. Results: The PCBF measured a mean of 109.08 ± 14.54 percent and 68.24 ± 10.47 percent in control group and caerulein group, respectively. Caerulein group had a mean decrease of 31.75 ± 16.79 percent. The serum amylase was 1323.70 ± 239.l0U.I-1 and 2184.60 ± 700.46U.I-1 in control and caerulein groups, respectively. There was a significant difference in the PCBF (p<0.05) and serum amylase (p<0.05) when compared to control and caerulein groups. Although micro and microvacuolization were seen in 30 percent in caerulein group, no significant difference was seen between the groups. Conclusion: A decrease in the PCBF may be one of the leading events and it is present before histopathological tissue injury had been established in this model of acute pancreatitis.
Assuntos
Animais , Masculino , Ratos , Ceruletídeo/efeitos adversos , Fluxometria por Laser-Doppler , Pâncreas/irrigação sanguínea , Pancreatite , Doença Aguda , Fluxo Sanguíneo RegionalRESUMO
Purpose: Reactive oxygen species (ROS) inactivation was studied to determine alterations in the pancreatic capillary blood flow (PCBF) during caerulein-induced pancreatitis in rats. Methods: A laser-Doppler flowmeter to measure PCBF and N-t-Butyl-Phenylnitrone (PBN) compound to inactivate ROS were used. Forty rats were divided in groups: 1) control; 2) caerulein; 3) PBN; 4) caerulein+PBN. Serem biochemistry and histopathological analyses were performed. Results: PCBF measured a mean of 109.08 ± 14.54 percent, 68.24 t 10.47 percent, 102.18 ± 10.23 percent and 87.73 ± 18.72 percent in groups 1, 2, 3 and 4, respectively. PCBF in groups 2 and 4 decreased 31.75 ± 16.79 percent and 12.26 ± 15.24 percent, respectively. Serum amylase was 1323.70 ± 239.10 U/l, 2184.60 ± 700.46 U/1, 1379.80 t 265.72 U/1 and 1622.10 ± 314.60 U/1 in groups 1, 2, 3 and 4, respectively. There was a significant difference in the PCBF and serem amylase when compared groups 2 and 4. Cytoplasmatic vacuolation was present in groups 2 and 4. Otherwise, no qualitative changes were seen. Conclusion: ROS inactivation improves PCBF and minimizes the serem amylase increase during caerulein-induced pancreatitis. ROS effect may be one of the leading causative events in this model of acute pancreatitis.
Assuntos
Animais , Masculino , Ratos , Ceruletídeo/efeitos adversos , Espécies Reativas de Oxigênio/efeitos adversos , Pâncreas/irrigação sanguínea , Pancreatite , Doença Aguda , Fluxometria por Laser-Doppler , Fluxo Sanguíneo RegionalRESUMO
A administracao de ceruleina tanto por via endovenosa como intraperitonial, tem sido extensivamente utilizada para inducao de pancreatite aguda experimental. Com objetivo de se testar uma nova metodologia de inducao de pancreatite aguda, que fosse de facil e rapida execucao, assim como de boa reprodutibilidade , 40 ratos Wistar foram distribuidos em quatro grupos: GRUPO I - animais que receberam infusao continua de ceruleina (15µ/Kg) GRUPO II - animais que receberam infusao continua e salina GRUPO III - animais submetidos a duas injecoes (SC+CV) de ceruleina (40µ/Kg) GRUPO IV - animais submetidos a duas injecoes (SC+CV) de salina. Apos a realizacao de dosagens bioquimicas, nao houve diferenca estatisticamente significativa entre os grupos I e II nas concentracoes teciduaias de tripsionogenio, quimiotripsinogenio, proelastase , catepsina e tambem amilase serica; ocorrendo diferenca somente entre os valores de porcentagem de agua no tecido pancreatico...