The Fick principle was used to aetermine the rate of hepatic utilization of lactic acid in dogs. Noncannulating electromagnetic flowmeters measured portal vein and hepatic artery flows. The ratio of gastroduodenal artery to common hepatic artery flow was constant (0.25) in four dogs so that true hepatic artery perfusion could be reliably estimated from common hepatic artery flow measurements. The transhepatic lactate concentration difference was determined from systemic arterial, portal venous, and "mixed hepatic" venous blood. Mixed hepatic venous blood samples, obtained from a catheter in the suprahepatic vena cava one minute following infrahepatic caval occlusion, were considered more representative of hepatic effluent than single hepatic vein blood since lactate concentrations of blood from different hepatic veins simultaneously sampled showed significant variability (0.20 ± 0.02 millimols/liter). The data suggests negligible hepatic metabolism of lactate in the resting, anesthetized state.
Goldstein PJ, Tashkin DP, Simmons DH. A Method for Studying Hepatic Metabolism in the DogI. Resting Lactate Metabolism. Arch Surg. 1971;102(2):127-131. doi:10.1001/archsurg.1971.01350020037010