Hypoxia and oxidative stress: The role of the anaerobic gut, the hepatic arterial buffer response and other defence mechanisms of the liver

The liver is considered a vital organ and is the hub for multiple chemical functions, such as intermediary metabolism and the detoxification of ingested toxins, which are essential for the preservation of life, hence, the origin or the word "liver". The liver has enormous, highly diversified catalytic potential. This enormous catalytic potential generates massive oxidative stress, which is important for the functions of the liver but is detrimental to the viability of the liver. The liver receives approximately 80% of its blood supply from the portal vein, which brings less saturated blood from the gastrointestinal tract.Hepatocytes operate in a relatively hypoxic microenvironment due to this portal inflow. The development of this hypoxic microenvironment of the liver is an important evolutionary adaptation for its detoxification function that is not recognized in the literature as a defence mechanism against the oxidative stress generated during the detoxification process. This review describes liver function in relation to its oxidative catalytic potential and the oxidative stress generated by it as well as the evolutionary defence mechanisms present in the liver against this oxidative stress to provide new insights into liver function.