Effect of lipopolysaccharide on viability of rat alveolar macrophages

Objective To evaluate the effect of lipopolysaccharide (LPS) on the viability of rat alveolar macrophages. Methods The rat alveolar macrophages were seeded in 96-well plate at a density of 4×104/ml.After being cultured for 24 h, the cells were randomly divided into 6 groups (n=5 each) using a random number table: control group (group C), LPS 0.1 μg/ml group (group LPS0.1), LPS 1.0 μg/ml group (group LPS1.0), LPS 10.0 μg/ml group (group LPS10), LPS 5.0 μg/ml group (group LPS50), and LPS 100.0 μg/ml group (group LPS100). Phosphate buffer solution was added to the culture medium in group C, and LPS with the final concentrations of 0.1, 1.0, 10, 50.0 and 100.0 μg/ml were added to the culture medium in LPS0.1, LPS1.0, LPS10, LPS50, and LPS100 groups, respectively.At 6, 12, 24 and 48 h after addition of PBS or LPS, the cell viability was measured by methyl thiazolyl tetrazolium assay. Results Compared with group C, the viability of alveolar macrophages was significantly increased at 6 and 12 h after addition of LPS in the other five groups , and was decreased at 24 and 48 h after addition of LPS in groups LPS50and LPS100(P 0.05). Conclusion Incubation with LPS 0.1–100.0 μg/ml for less than 12 h can enhance the viability of rat alveolar macrophages; incubation with LPS with the concentration ≥ 50.0 μg/ml for more than 24 h can decrease the cell viability. Key words: Lipopolysaccharide; Macrophages, alveolar