Do opioid receptors play a role in the pathogenesis of the inflammatory response in acute pancreatitis?

Abstract

PURPOSE:To investigate the effect of the opioid blocker naltrexone in the inflammatory response in acute pancreatitis (AP). METHODS: Acute pancreatitis was induced in anesthetized male Wistar rats by retrograde injection of 2.5% sodium taurocholate diluted in 0.5ml saline into the main pancreatic duct. Animals were randomized to the following experimental groups: Control Group (n=9): animals received an intraperitoneal injection of saline solution (0.5ml), 15 minutes before the induction of AP. Naltrexone Group (n=9): animals received an intraperitoneal injection of naltrexone 0.5ml (15 mg/kg), 15 minutes before induction of AP. Peritoneal levels of TNF-α and serum levels of IL-6 and amylase were determined The volume of the ascitic fluid was also evaluated. Myeloperoxidase (MPO) activities were analyzed in homogenates of pulmonary tissue. RESULTS: There were no significant differences in the ascitic fluid volume, nor in TNF-a and IL-6 levels in the naltrexone group compared to controls. Treatment with naltrexone did not affect the lung MPO activity compared to control group. CONCLUSIONS: The opioid receptors don't play an important role in the pathogenesis of the inflammatory response in acute pancreatitis. If opioids affect leukocytes inflammatory signaling, there are no major implications in the pathogenesis of acute pancreatitis. Key words: Pancreatitis. Physiopathology. Receptors, Opioid. Naltrexone. Rats. RESUMO OBJETIVO:Investigar o efeito do bloqueador opióide naltrexone na resposta inflamatória da pancreatite aguda. METODOS: Pancreatite aguda foi induzida em ratos machos Wistar, através de injeção retrógada de solução de taurocolato de sódio a 2,5% nos ductos pancreáticos. Os animais foram alocados em dois grupos: Grupo controle (n=9) animais receberam 0,5 ml de solução salina intra-peritonial 15 minutos antes da indução da pancreatite aguda e Grupo naltrexone (n=9) animais receberam naltrexone (15mg/ kg de peso), em 0,5 ml de volume final por via intraperitoneal, 15 minutos antes da indução da pancreatite aguda. Foram avaliados o volume de ascite, os níveis séricos de amilase e IL-6, assim como TNF-α peritoneal e a atividade da mieloperoxidase (MPO) no tecido pulmonar. RESULTADOS: Não foram encontradas diferenças significantes nos parâmetros analisados entre o grupo que recebeu solução salina e o que recebeu naltrexone . CONCLUSÕES: Os receptores opióides não desempenham papel importante na resposta inflamatória sistêmica associada à pancreatite aguda. Se os opioides alteram a sinalização inflamatória nos leucócitos está ação não se reflete na patogênese da pancreatite aguda Descritores: Pancreatite. Fisiopatologia. Receptores Opióides. Naltrexona. Ratos. Do opioid receptors play a role in the pathogenesis of theinflammatory response in acute pancreatitis?

Emodin and baicalein inhibit sodium taurocholate-induced vacuole formation in pancreatic acinar cells

“…The pathogenesis of SAP remains poorly understood[ 21 ]. One hypothesis posits that inflammatory reactions are crucial for the pathogenesis of SAP[ 22 ]. Local inflammatory reactions in the pancreas lead to systemic inflammatory response syndrome (SIRS) and multiorgan failure (MOF), which is believed to be the primary cause of mortality[ 23 ].…”

Molecular mechanisms of pain in acute pancreatitis: recent basic research advances and therapeutic implications

“…On the other hand, morphine therapy worsened the severity of AP and impeded resolution and regeneration of the pancreas ( Barlass et al, 2018 ), whereas another study indicated that morphine decreased vacuolization in edematous AP ( Bálint et al, 2022 ). Additionally, the opioid blocker naltrexone did not affect the pancreatic pathology and the inflammatory response ( Penido et al, 2012 ).…”