Hepatic and Renal Metabolism

Hepatic cirrhosis with portal hypertension and gastroesophageal hemorrhage is a disease complex that continues to be treated by surgical portasystemic shunts. Whether or not a reduction or diversion of portal blood flow to the liver adversely affects the ability of the liver to maintain fuel homeostasis via gluconeogenesis, glycogenolysis, and ketogenesis is unknown. 11 patients with biopsy-proven severe hepatic cirrhosis were studied before and after distal splenorenal or mesocaval shunts. Hepatic, portal, and renal blood flow rates and glucose, lactate, pyruvate, glycerol, amino acids, ketone bodies, free fatty acids, and triglyceride arteriovenous concentration differences were determined to calculate net precursor-product exchange rates across the liver, gut, and kidney. The study showed that hepatic contribution of glucose and ketone bodies and the caloric equivalents of these fuels delivered to the blood was not adversely affected by either a distal splenorenal or mesocaval shunt. In addition to these general observations, isolated findings emerged. Mesocaval shunts reversed portal venous blood and functionally converted this venous avenue into hepatic venous blood. The ability of the kidney to make a substantial net contribution of ketone bodies to the blood was also observed.