Intravenous zymosan-A challenge induces an alveolar inflammatory response

The purpose of this study was to evaluate the ability of intravenous zymosan-A (ZyA) challenge to induce an alveolar inflammatory response as indicated by inflammatory changes among lung lavage cells. The organ distribution of 1 mg of [51Cr]ZyA revealed that immediately following intravenous challenge of female ICR mice approximately 81% of the total cpm injected was associated with pulmonary tissue. Approximately 15% of the injected cpm was associated with the peripheral blood, liver, and spleen. ZyA translocated from the vascular compartment into pulmonary alveoli and was detected within polymorphonuclear neutrophils (PMN) and alveolar macrophages (AM) 18 h after intravenous challenge. PMN numbers among lung lavage cells increased beginning one day after challenge to a peak of approximately 5 x 10(5) PMNs by day 3 after challenge. The PMN response subsided by day 5 after challenge. There was no significant increase in the numbers of AM during the first week after intravenous ZyA; however, the number of AM increased from approximately 5 x 10(5) AM on day 1 after challenge to approximately 1.1 x 10(6) AM by day 5 after challenge. Within 24 h of intravenous ZyA, the number of AM in S phase of the cell cycle increased from approximately 2.5 x 10(4) AM one day after challenge to 1.1 x 10(5) AM in S phase five days after challenge. The data suggest that intravenous ZyA localized within pulmonary tissue immediately following intravenous challenge and translocated into the alveolar compartment where ZyA particles were found within phagocytes.(ABSTRACT TRUNCATED AT 250 WORDS)