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1. Tissue Regeneration and Glycans |
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● Collagen binding of vitronectin regulated by change in glycans Vitronectin is produced in the liver, exists in blood and binding tissue, and is concerned with various regulations such as coagulation and complement immunity system. For example, we add serum of cow fetus for cellular cultivation, and for which a very small amount of vitronectin is important for extension of cellular binding. However, even though it shows activation in a test tube, we have not completely found out its actual function in a living system. We have analyzed the structure of glycan and protein part of vitronectin, and in recent years, we have had a chance to examine vitronectin contained in blood of rat with regenerated liver. The liver has an amazing regenerative ability that it can grow to the original size in 10 days after removed below one third in surgery. The amount of blycochains and the structure of vitronectin made by the liver during regeneration extremely change, and at the same time activation of collagen binding is increased by several times comparing with a normal rat. However, even though the level was low, not only in vitronectin produced by a regenerated liver but vitronectin in a rat which got Siam surgery (abdominal surgery in which the liver is not removed and sutured as before), the same change occurred. We had examined what would change when we artificially remove glyco-chains from vitronectin by using enzymes in a test tube 1). Now we are very happy that we were able to see almost the same change occurring in a living system. Vitronectin may play an important role in the regeneration of tissue and restoration of a wound. After removal of the liver in surgery, the amount of glycoprotein produced by the liver decreases once, and also the amount of vitronectin decreases below half. Therefore, a qualitative change mainly in glycans in vitronectin may make up for the decrease of the amount. By finding an example like above, we are interested in “the relationship between glycans and tissue restoration in acute state” and go on with the research 2).
1)
Yoneda A., et al. (1998)
Biochemistry
13
, 555-566
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