part of part of overlaps Mammalia hepatic acinus hepatic acinus zone 1 The region of the hepatic acinus that is closest to the arterial blood supply and has the highest oxygen concentration. Zone 1 is located in the periportal region of the liver lobule, closest to the portal triad. Hepatocytes in this region are primarily involved in oxidative energy metabolism. 2020-09-08T14:14:21Z hepatic acinus periportal zone UBERON:8400001 metabolic zone of liver liver lobule periportal region