Acid glycosaminoglycans in experimental pleural effusions.

Acid glycosaminoglycans (GAG) were quantitated and partially characterized in pleural effusions in guinea pigs with experimental allergic pleurisy. (a) Increase of GAG in the pleural effusion preceded the increase of effusion volume. Effusion was associated with the presence of cuboidal mesothelial cells on visceral pleura, and hemorrhage, infiltration of neutrophils, and destruction of the alveolar structure of the lung. (b) A significant difference was found in the relative percentage of GAG subtypes in the effusion, serum, and the lung tissue of guinea pigs with experimental pleurisy. (c) There was a difference in molecular size of hyaluronic acid in pleural effusion between the early and late stages of pleurisy. (d) Presumably GAGs found in pleural effusion were released from the pleural tissue.