Increased plasma concentrations of hyaluronan after major thermal injury in the rat

Hyaluronan (HYA) is an ubiquitous polysaccharide in connective tissue interstitium; its normal plasma concentration is in the nanogram/ml range. Following major burn injury in sheep, plasma HYA can increase to levels tenfold greater than normal. The present study aimed to determine the effects of major cutaneous burns on plasma HYA concentration in rat, since in this species, the HYA elimination kinetics may better resemble those in man. Thermal injury did not alter the weight-average molecular weight of HYA in skin. HYA concentration in plasma was 46 +/- 4 ng/ml (mean +/- SEM) in controls. Three hours after scald burns to 40% of the body surface area, plasma HYA was 61 +/- 10 ng/ml in unresuscitated animals (P less than 0.1 vs. controls). After fluid replacement by lactated Ringer's plasma HYA was 75 +/- 8 ng/ml (P less than 0.01 vs. control), whereas plasma infusion prevented the elevation of plasma HYA. HYA also increased significantly after lactated Ringer's infusion in noninjured animals. The increased plasma concentration of HYA after major burns is probably a consequence of increased lymph flow, increasing its transport from skin interstitium. Possibly, plasma concentrations of connective tissue components may be used as indicators of the severity and extent of burn injuries.