(1 3)-b-D-glucans are a diverse group of naturally occurring glucose polymers. They have been demonstrated to have a range of stimulatory effects on various cell types including macrophages^1,2 and at an experimental level appear to have a role in respiratory changes induced by the inhalation of organic dusts³.

Studies carried out by our group into the effects of inhalation of (1 3)-b-D-glucan (isolated from baker's yeast - glucan (BY)) demonstrate changes in airway responsiveness in the guinea pig airway. In vitro, there is a decrease in sensitivity to a variety of constrictors after exposure to glucan (BY)⁴. Changes in the histamine release characteristics of mast cells also occur after exposure to BY glucan⁵.

In vivo changes in responsiveness occur in the guinea pig at certain time points post - glucan exposure. A significant eosinophilia has also been shown at several glucan dose levels. These findings will be discussed in relation to the role that glucans may play in the induction of environmental respiratory disease.