Effect of oral administration of AZD8309, a CXCR2 antagonist, on the severity of experimental pancreatitis.

INTRODUCTION: Acute pancreatitis is a common gastrointestinal disorder burdened with a high mortality. Two pathophysiological events during experimental pancreatitis are thought to determine the clinical course: premature digestive protease activation and tissue infiltration by inflammatory cells. We have investigated the effect of AZD8309, a potent and orally bioavailable antagonist of the chemokine receptor CXCR2, which has been proposed to regulate the transmigration of neutrophils. METHODS: Male C57BL6 mice (25-30 g) received gavage feeding of AZD8309 (50 mg/kg/BW) or mannitol (controls) twice daily starting 3 h prior to pancreatitis induction. Mild pancreatitis was induced by i.p. caerulein administration (50 µg/kg BW), severe pancreatitis by intraductal taurocholate (2%). Pancreas, lung, and serum was harvested up to 48 h after pancreatitis induction and used for histopathology, amylase, lipase, cathepsin B, trypsin, and elastase activity measurements, myeloperoxidase (MPO) content and cytokine concentrations. RESULTS: Oral administration of AZD8309 significantly reduced MPO in the pancreas and lungs (8 h & 24 h) and reduced intrapancreatic trypsin and elastase activity (8 h) in caerulein-pancreatitis. In taurocholate-pancreatitis AZD8309 reduced cathepsin B activity and MPO. Serum cytokine levels were reduced by AZD8309 as well as histopathological damage. CONCLUSION: The CXCR2 antagonist AZD8309 reduced the transmigration of neutrophils as well as intrapancreatic protease activation in experimental pancreatitis. This effect was sufficient to reduce the overall severity of the disease. CXCR2 may therefore be a viable therapeutic target and AZD8309 a suitable agent for the treatment of acute pancreatitis.

Advances in the etiology of chronic pancreatitis.

In the past, chronic pancreatitis has been regarded as a fairly uniform and largely untreatable disorder that most commonly affects patients who both lack gainful employment or adequate insurance coverage and have a tendency to smoke and drink. Large clinical trials suggest that this perception is not only misguided and discriminatory but also not based on facts. We forgot that the perception of chronic liver disease was similar before World War II, and just like liver cirrhosis the fibrosis and cirrhosis of the pancreas--i.e. chronic pancreatitis--is the end result of a range of environmental, inflammatory, infectious and genetic disorders. A growing number of these have only recently been recognized as a distinct entity and several of which are becoming truly treatable. A large proportion of the risk for developing pancreatitis is conveyed by genetic risk factors, and we estimate that less than half of those have been identified so far. The same holds true for protective factors that can prevent pancreatitis, even in the face of excessive alcohol abuse. Various gene mutations and polymorphisms appear to determine an individual's susceptibility for developing pancreatic disease, for the severity of the disease, and for the disease progression. The spectrum of genotype/phenotype associations ranges from straightforward autosomal dominant traits with near-complete penetrance, as for the most common mutations in the cationic trypsinogen gene (PRSS1), to moderate risks factors without mendelian inheritance patterns, as for SPINK1 and CFTR mutations, to very subtle risk associations and disease modifiers that can only be identified in large cohort studies, as for the chymotrypsin C, calcium-sensing receptor and the anionic trypsin (PRSS2) mutations. Only a better understanding of the disease mechanisms that underlie these changes will make an individualized therapy of pancreatic disorders a realistic option.