Metabolism collagen types

Sodek J and Mandell SM (1982) Collagen metabolism in rat incisor predentin in vivo synthesis and maturation of type I, cxi(I) trimer, and type V collagens. Biochemistry 21, 2011-2015. 

Zhu, C. F., Li, G. Z., Peng, H. B., Zhang, F., Chen, Y., and Li, Y. (2010). Effect of marine collagen peptides on markers of metabolic nuclear receptors in type 2 diabetic patients with/without hypertension . Biomed. Environ. Sci. 23,113-120. 

This section discusses two families of structural proteins, namely, extracellular keratins and collagens. Each example represents a family of closely related chemical entities, which means dealing with complex protein mixtures. We consider two types of chemical modifications modifications arising from increased levels of glucose in body fluids (obviously related to diabetes) and those derived from acetaldehyde, the first metabolic product of ethanol ingestion. As noted, a common feature of the latter nonenzymatic modification reactions is the presence of an aldehydic functionality in the nonprotein reactant (Jelfnkovd et al 1995 Deyl and Mikgik, 1995). 

The major functioning cells in the liver are the hepato-cytes, responsible for about 70% of liver mass and performing most of the metabolic and synthetic functions of the liver. Two other cell types are found in small numbers within the liver. The stellate cells (sometimes referred to as Ito cells) are located between the endothelial lining of sinusoids and the hepatocytes within a small cleft referred to as the space of Disse. In their normal, quiescent state, stellate cells serve as a site of storage for fat soluble vitamins, particularly vitamin A. Wlien stimulated, stellate cells are transformed both morphologically and functionally. They synthesize collagen, and are the cells responsible for fibrosis and, eventually, cirrhosis. They synthesize nitric oxide, which helps to regulate intrahepatic blood flow. 

ICTP, C-terminal telopeptide of type I collagen. (From Robins SR Biochemical markers of bone metabolism. CPD Bulletin Clin Biochem 1999 1 116-21.)... 

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