Effect of D-glucosamine on the content and synthesis of UDP-sugars and plasma membrane associated carbohydrates in chicken liver and hepatoma Mc-29.

1. Comparative studies on the effect of D-glucosamine on the synthesis of UDP-sugars and on the incorporation rate of [14C]glucose into neutral sugars, sialic acid and glucosamine isolated from chicken liver and hepatoma Mc-29 plasma membranes have been carried out. 2. The influence of D-glucosamine on the activity of microsomal UDP-N-acetylglucosamine: glycoprotein N-acetylglucosaminyltransferase to lipid (dolichol monophosphate) and to protein acceptor was studied too. 3. It has been shown that D-glucosamine provokes alterations in the content and synthesis of UDP-sugars and it is an inhibitor of the glycosylation processes. An inhibitory effect of this sugar analog on the N-acetylglycosaminyltransferase has been established.