The effects of dobutamine, dopexamine and fluid on hepatic histological responses to porcine faecal peritonitis

Abstract

We studied the effects of two catecholamines with differing receptor profiles on hepatic blood flow and hepatic structure in a porcine model of faecal peritonitis. We treated animals with dopexamine (group Dp) or dobutamine (group Db) and fluid, or fluid alone as a control, to achieve a 2.5% increase in Q_t from baseline values. After the induction of faecal peritonitis the increased Q_t was maintained throughout the 8 h study period by adjustment of the fluid infusion rate. The dose of catecholamines remained constant. Hepatic blood flow was correspondingly maintained at above baseline values throughout the study. Post-mortem liver biopsy specimens were analysed from experimental animals and t sham animals who had not been instrumented or infected. In experimental animals there was a reduction in sinusoidal patency between sham and group Dp (76% of total sinusoid vs 51%,p<0.05) and group Dp and control (51% vs 33%,p<0.05) or groups Dp and Db (51% vs 34%,p<0,05) animals. This was accounted for by an increase in sinusoidal leukocytes and endothelial swelling. In addition to the changes noted above there was marked hepatocellular destruction in group Db. We conclude that maintenance of organ blood flow does not guarantee structural integrity in the sepsis syndrome and hepatocellular damage was greater in group Db than group Dp or control.