Abstract
Portal and hepatic flows of metabolites have been paid much attention in feeding and nutritional studies. Ultrasound-guided percutaneous punctures of portal and hepatic veins were performed in standing using 17 cattles (12 cows and 5 heifers), and those plasma glucose, acetic acid, 3 - hydroxybutyric acid (3 - HB) levels, blood gas tension and pH were compared with ear arterial blood (only for gas tension and pH) and jugular blood. Percutaneous catheterization in the portal or hepatic veins were performed in 3 cattles. Usinig the catheters, continuous sampling from the hepatic vein, or portal injection were carried out. Portal vein was characterized by thick hyperechogenic wall compared to hypoechogenic hepatic vein, therefore a distinction between them was easy by watching the ultrasound screen. Abnormalities like as fever, anorexia were not observed after the puncture and catheterization. Plasma acetic acid and 3-HB levels of portal and hepatic vein were markedly higher than those of jugular plasma. Among the 3 veins, highest plasma glucose level was observed in the hepatic veins in most animals. Portal blood showed marked higher oxygen tension than the blood of other two veins. On continuous blood sampling from the jugular and hepatic vein via the catheters, an elevation of glucose level after oral propylene glycol administration was much larger in the hepatic vein than that in the jugular vein. There was no difference in glucose clearance from the peripheral circulation between portal and jugular injections of glucose. Benefit for nutritional studies and safety of the ultrasound-guided percutaneous puncture and catheterization of the portal and hepatic veins were confirmed.
