The liver is an exceptionally complex and diverse organ that functions both as an exocrine and an endocrine gland. It secretes bile, which contains many con stituents in addition to bile salts, and it synthesizes and releases many substances in response to the body's demands, including prohormones, albumin, clotting factors, glucose, fatty acids, and various lipoproteins. It has a dual blood supply providing a rich mixture of nutrients and other absorbed substances via the portal vein and oxygen-rich blood via the hepatic artery. This functional heterogeneity is accompanied by cellular heterogeneity. The liver contains many cell types including hepatic parachymal cells, Kiipffer cells, Ito cells, and endothelial cells. The most abundant cell type, the parenchymal cells, are biochemically and structurally heterogeneous. The cells in the oxygen-rich areas of the portal triad appear more dependent on oxidative metabolism, whereas those around the central vein (pericentral, perivenous, or centrolobular areas) are more dependent upon an anaerobic mechanism. Throughout this volume the latter three terms are used synonymously by various authors to indicate the five to eight layers of cells radiating from the central vein. Structural and metabolic heterogeneity of hepatic parenchymal cells has been demonstrated by a variety of approaches, including histochemical, ultra structural, and ultramicrobiochemical studies. This microheterogeneity is linked to the physiological functions of the liver and its response to injurious substances.Additional work is required to establish the precise sequence of events that lead to either massive or zonal necrosis by any ... The oxidation of allyl alcohol has been shown to require NADaquot;-linked alcohol dehydrogenase.a Using liver homogenates and isolated mitochondria, Serafini-Cessio demonstrated that allyl alcohol was converted into acrolein, an aldehyde that can be subsequently oxidized toanbsp;...
|Title||:||Regulation of Hepatic Metabolism|
|Author||:||K. Jungermann, F.C. Kauffman, R.G. Thurman|
|Publisher||:||Springer Science & Business Media - 2012-12-06|