EFFECT OF GLUCAN ON MURINE LUNGS

Glucan, a folded high-molecular-weight polysaccharide, has multiple ef fects in animals when administered intravenously or intraperitoneally, but not when administered by inhalation. The hypotheses tested were w hether intratracheal administration of glucan can cause lung damage an d whether some of the resulting lung injury is immunologically mediate d. There was a dose-response relationship between the amount of intrat racheally injected glucan and the extent of pulmonary histologic abnor malities, which consisted of peribronchiolar and intraalveolar infiltr ation with chronic inflammatory cells. An attempt to adoptively transf er increased susceptibility to glucan induced lung injury was made. Ce lls cultured with glucan were transferred into naive recipients before intratracheal glucan exposure. The extent of pulmonary inflammation t hat occurred as a result of intratracheal injection of glucan was not affected by transfer of cultured cells from glucan-treated animals. Ho wever, high concentrations of glucan in culture did produce cells with the appearance of lymphoblasts. These data indicate that glucan induc es lung injury, but that there is no evidence of cell mediation of pul monary injury induced by intratracheal exposure to glucan.