The effects of zymosan-activated plasma(ZAP)on lung fluid exchangeand on superoxide anion production by granulocytes were studied in 8 consciousgoats with chronic lung lymph fistula,It was found that after ZAP infusion, thecirculating granulocytes were activated and the release of superoxide anions wasmarkedly enhanced. There was an increase in lung lymph flow and proteinconcentration.It suggests that the superoxide anion released by the stimulatedgranulocytes can play a role in inducing lung injury by the activated complement. The effects of zymosan-activated plasma (ZAP) on lung fluid exchange and on superoxide anion production by granulocytes were studied in 8 consciousgoats with chronic lung lymph fistula, It was found that after ZAP infusion, the circulating granulocytes were activated and the release of superoxide anions wasmarkedly enhanced. There was an increase in lung lymph flow and protein con- centration. It suggests that the superoxide anion released by the stimulated granule cells play a role in inducing lung injury by the activated complement.