Ethanol administration impairs pancreatic repair after injury.

OBJECTIVES: Alcohol abuse is one of the most common factors associated with acute and chronic pancreatitis. Although it is evident that alcohol abuse can have an important role in the development of pancreatitis, it does not seem that alcohol abuse alone is responsible for this disease. We investigated the involvement of ethanol in the impairment of pancreatic repair after induction of pancreatitis. METHODS: A biologically relevant mouse model of alcoholic pancreatitis, combining long-term ethanol consumption and coxsackievirus infection, was used to investigate the effects of ethanol on pancreatic regeneration. Tissues were harvested and analyzed by reverse transcription-polymerase chain reaction and immunoblot. RESULTS: These studies demonstrate that long-term ethanol consumption impairs the structural repair of the exocrine pancreas. This is accompanied by a delay in the restitution of lipase expression. In addition, impaired expression of the critical pancreatic transcription factors, PDX1 and PTF1, and the mediator of Notch signaling, HES1, was observed. CONCLUSIONS: Long-term ethanol consumption impairs the structural repair and functional restitution of the pancreas after severe injury. These impairments may, in part, be explained by the impaired expression of factors important in the development and maintenance of the exocrine pancreas. Impaired pancreatic regeneration may have a role in the pathogenesis of alcoholic pancreatitis.

Alcoholic pancreatitis: mechanisms of viral infections as cofactors in the development of acute and chronic pancreatitis and fibrosis.

Acute and chronic pancreatitis is associated with alcohol abuse, but symptomatic pancreatitis develops in only a small proportion of persons (10-20%) who abuse alcohol. This apparent paradox has led to the notion that additional cofactors are involved in the development of alcoholic pancreatitis. Potential cofactors, such as diet and smoking, have been suggested, but there are no compelling epidemiologic data to support this idea. A number of viruses and some bacteria have been shown to infect the pancreas and produce pancreatitis. One important mediator of pancreatitis in persons with a compromised immune system is a viral infection. The increased susceptibility of immunocompromised persons to viral pancreatitis led to the hypothesis, described in this paper, that the well-known immunosuppression associated with alcohol abuse would result in a more severe viral pancreatitis in mice, which are provided ethanol, than in control animals. To test this hypothesis, C57BL/6 mice were infected with a virulent strain of coxsackievirus B3, which preferentially induces pancreatitis, or with a strain that is naturally avirulent. The study findings presented in this paper show that ethanol consumption alone does not produce pancreas damage but results in a more severe and prolonged pancreatitis after infection with a virulent virus and interestingly, after infection with the avirulent strain of virus. This was associated with an increased number of viruses in the pancreas and spleen, which correlated with decreased humoral immune responses to the virus.

Ethanol consumption potentiates viral pancreatitis and may inhibit pancreas regeneration: preliminary findings.

Alcohol abuse is often associated with acute pancreatitis. The pathogenesis of alcoholic pancreatitis remains poorly understood, in part because of the lack of a suitable animal model to study the mechanism or mechanisms of this disease. It has been proposed that ethanol predisposes or sensitizes the pancreas to the effects of co-factors, and the combination of the effects of ethanol on the pancreas and the actions of these co-factors results in alcoholic pancreatitis. A number of viruses are known to infect the pancreas, and we have suggested that one co-factor that could be involved in the development of alcoholic pancreatitis is a viral infection. One of the most-studied groups of viruses that infect the pancreas and cause pancreatitis in human beings is the coxsackieviruses. We have shown that short-term (5-14 days) and subchronic (>28 days) administration of ethanol to mice increases the severity of coxsackie B3-induced pancreas damage. We hypothesize that consumption of ethanol would result in an impairment of pancreas regeneration after injury, similar to the effect of ethanol on liver regeneration. With the use of the murine model of coxsackie B3-mediated alcoholic pancreatitis we have obtained preliminary data to support the hypothesis. Specifically, consumption of ethanol by mice is associated with changes in the replication of acinar cells and their organization into acini after viral-mediated injury. We believe that this model will be a valuable tool to study the biochemical and molecular mechanisms involved in alcoholic pancreatitis.

Animal model of alcoholic pancreatitis: role of viral infections.

Pancreatitis is clearly associated with alcohol abuse, but only a relatively small percentage of people who abuse alcohol develops obvious pancreatitis. These observations have led to the concept that the development of alcoholic pancreatitis requires cofactors. Although diet and smoking have been studied, a clear cofactor has not been identified. The study results presented in this paper were obtained to determine whether viral infection of the pancreas would be a cofactor for alcoholic pancreatitis similar to the role of hepatitis virus infections in the development of alcoholic liver disease. To test this hypothesis, mice were fed ethanol with a liquid diet protocol and infected with coxsackievirus B3 (CVB3). It was found that consumption of alcohol alone did not result in pancreatitis as determined by serum levels of amylase or histologic changes in the pancreas. Two strains of CVB3 that are tropic for the pancreas were used; a virulent and an avirulent strain. Infection of alcohol-fed animals with the virulent CVB3 strain 28 resulted in a more severe pancreatitis than the pancreatitis noted in control animals. Alcohol-fed mice infected with the avirulent strain (GA) showed severe pancreatitis, whereas the infection of control mice did not result in obvious pathologic effects in the pancreas. This model allows mechanistic studies to define the role of viral infection as a cofactor for alcoholic pancreatitis.