Effect of acetyl-L-carnitine on hypersensitivity in acute recurrent caerulein-induced pancreatitis and microglial activation along the brain’s pain circuitry

BACKGROUND Acute pancreatitis(AP)and recurring AP are serious health care problems causing excruciating pain and potentially lethal outcomes due to sepsis.The validated caerulein-(CAE)induced mouse model of acute/recurring AP produces secondary persistent hypersensitivity and anxiety-like behavioral changes for study.AIM To determine efficacy of acetyl-L-carnitine(ALC)to reduce pain-related behaviors and brain microglial activation along the pain circuitry in CAE-pancreatitis.METHODS Pancreatitis was induced with 6 hly intraperitoneal(i.p.)injections of CAE(50μg/kg),3 d a week for 6 wk in male C57BL/6J mice.Starting in week 4,mice received either vehicle or ALC until experiment’s end.Mechanical hypersensitivity was assessed with von Frey filaments.Heat hypersensitivity was determined with the hotplate test.Anxiety-like behavior was tested in week 6 using elevated plus maze and open field tests.Microglial activation in brain was quantified histologically by immunostaining for ionized calcium-binding adaptor molecule 1(Iba1).RESULTS Mice with CAE-induced pancreatitis had significantly reduced mechanical withdrawal thresholds and heat response latencies,indicating ongoing pain.Treatment with ALC attenuated inflammation-induced hypersensitivity,but hypersensitivity due to abdominal wall injury caused by repeated intraperitoneal injections persisted.Animals with pancreatitis displayed spontaneous anxiety-like behavior in the elevated plus maze compared to controls.Treatment with ALC resulted in increased numbers of rearing activity events,but time spent in“safety”was not changed.After all the abdominal injections,pancreata were translucent if excised at experiment’s end and opaque if excised on the subsequent day,indicative of spontaneous healing.Post mortem histopathological analysis performed on pancreas sections stained with Sirius Red and Fast Green identified wide-spread fibrosis and acinar cell atrophy in sections from mice with CAE-induced pancreatitis that was not rescued by treatment with ALC.Microglial Iba1 immunostaining was significantly increased in hippocampus,thalamus(intralaminar nuclei),hypothalamus,and amygdala of mice with CAE-induced pancreatitis compared to naïve controls but unchanged in the primary somatosensory cortex compared to naïves.CONCLUSION CAE-induced pancreatitis caused increased pain-related behaviors,pancreatic fibrosis,and brain microglial changes.ALC alleviated CAE-induced mechanical and heat hypersensitivity but not abdominal wall injury-induced hypersensitivity caused by the repeated injections.

Favorable response after radiation therapy for intraductal papillary mucinous neoplasms manifesting as acute recurrent pancreatitis:A case report

BACKGROUND There has been an increasing number of elderly patients with intraductal papillary mucinous neoplasm(IPMN),who are surgically intolerant and require less invasive treatment options,which are limited.In the present study,we report a case of IPMN presenting with acute recurrent pancreatitis(ARP),in which radiation therapy effectively prevented further attacks of ARP and reduced tumor volume.CASE SUMMARY An 83-year-old man was referred to our hospital with an asymptomatic incidental pancreatic cyst.Endoscopic ultrasound imaging and magnetic resonance cholangiopancreatography revealed a multiloculated tumor in the head of the pancreas,with dilated pancreatic ducts and mural nodules.The patient was diagnosed with mixed-type IPMN,and five years later,he developed ARP.Several endoscopic pancreatic ductal balloon dilatations failed to prevent further ARP attacks.Surgery was considered clinically inappropriate because of his old age and comorbidities.He was referred to our department for radiation therapy targeted at those lesions causing intraductal hypertension and radiation was administered at a dose of 50 Gy.An magnetic resonance imaging scan taken ten weeks after treatment revealed a decrease in tumor size and improvement of pancreatic duct dilatation.Fourteen months later,he remains symptom-free from ARP.CONCLUSION This case highlights the important role of radiation therapy in mitigating the signs and symptoms of ARP in patients with inoperable IPMN.

Hereditary pancreatitis:An updated review in pediatrics

Hereditary Pancreatitis(HP)has emerged as a significant cause of acute,acute recurrent and chronic pancreatitis in the pediatric population.Given that it presents similarly to other causes of pancreatitis,a positive family history and/or isolation of a gene mutation are vital in its designation.Inheritance patterns remain complex,but mutations involving the PRSS1,SPINK1,CFTR and CTRC genes are commonly implicated.Since being first described in 1952,dozens of genetic alterations that modify the action of pancreatic enzymes have been identified.Among children,these variants have been isolated in more than 50%of patients with chronic pancreatitis.Recent research has noted that such mutations in PRSS1,SPINK1 and CFTR genes are also associated with a faster progression from acute pancreatitis to chronic pancreatitis.Patients with HP are at increased risk of developing diabetes mellitus,exocrine pancreatic insufficiency,and pancreatic adenocarcinoma.Management follows a multi-disciplinary approach with avoidance of triggers,surveillance of associated conditions,treatment of pancreatic insufficiency and use of endoscopic and surgical interventions for complications.With significant sequela,morbidity and a progressive nature,a thorough understanding of the etiology,pathophysiologic mechanisms,diagnostic evaluation,current management strategies and future research considerations for this evolving disease entity in pediatrics is warranted.