HYALURONAN METABOLISM IN RAT TAIL SKIN FOLLOWING BLOCKAGE OF THE LYMPHATIC CIRCULATION

Abstract

This study was undertaken to explore theeffects of lymphatic blockage on the metabolismof hyaluronan in the skin. In initialexperiments, PH] hyaluronan was injectedsubcutaneously into the tail skin of rats thateither had no surgical intervention (control)or into those that had their lymphaticdrainage blocked two hours earlier (acutelymphedema) or after the lymphatics had beenblocked for three months (chronic lymphedema).The removal of tritiated hyaluronanfrom the injection sites was determined by theappearance ofPH] in the plasma. The resultsshowed that the clearance of injectedhyaluronan was delayed in rats with lymphaticblockage. The half- life of injected hyaluronanin the controls was -70-75 hr, compared with-105-110 hr in the lymph blocking rats. Thelevels of radioactivity in the plasma from ratswith both acute and chronically blockedlymphatics were lower than that of controlrats during the entire follow up period. Inaddition, biochemical analysis revealed thatthere was a significant increased amount ofhyaluronan in the tail skin three months afterlymphatic blocking. These results suggest thatlymph absorption is an important factor in thetransport of hyaluronan from the interstitium.Blockage of regional draining lymphaticslikely impairs the catabolism of hyaluronan,which stagnates in skin tissue.