SP-A−/− mice were inoculated intratracheally with 106 CCU Ureaplasma ± 100 µg purified human SP-A and lungs harvested after 6, 24 or 48h. Total and differential cell counts were performed. Nitrite in BAL was measured after nitrate was reduced to nitrite with nitrate reductase, U. parvum inoculation alone, black bars; U. parvum plus SP-A inoculation, white bars. Data are expressed as the means ± SE of the total number of inflammatory cells (A), neutrophils (B), or, total NO (C). *p<0.05 vs Ureaplasma-inoculated SPA−/− 24h post-inoculation.