Biochemical and Cytological Aspects of Liver Cell Function During Infection
MADIGAN ARMY MEDICAL CENTER JOINT BASE LEWIS MCCHORD WA
Pagination or Media Count:
The primary emphasis of this chapter is on the effects of bacterial infection on the liver only because it is about the model that we have the most information. It should be noted that no attempt is made to review all the literature in this field. We do, however, attempt to present a general picture of what effects infection has on hepatic constituents, components and metabolism. The production of microbial exotoxins, the presence of lipopolysaccharide endotoxins and differences in distribution of microorganisms among different target tissues can modify the generalized host response and make difficult the differentiation between changes which are pathophysiological and those which are typically part of the host defense mechanisms. For these reasons many of the studies focuses on in this chapter were carried out in Streptococcus pneumoniae-infected rats. This experimental model represents an extracellular infection characterized by the absence of lipopolysaccharide and protein toxins so that changes in liver functions more closely represent nonspecific host adaptations to infection and inflammation. It is not certain how the myriads of changes observed in the liver during such a model infection are mediated. It is believed, however, that phagocytosis of invading microorganisms by host phagocytes results in the release of endogenous mediators which subsequently initiate a wide range of hepatic metabolic alterations. These endogenous mediators may produce their effects by acting directly on the liver, indirectly by stimulating the release of insulin, glucagon and other hormones, or via the central nervous system.
- Medicine and Medical Research