Objective   To determine the effect of LPS stimulation on the expression of PPARγ in rat type Ⅱ alveolar epithelial (AT-Ⅱ) cells.    Methods   Rat lung tissues were digested by trypsase and collagenase. AT-Ⅱ cells were isolated and purified by immuno-adherence

and then primarily cultured AT-Ⅱ cells were identified by alkaline phosphatase (AKP)

pulmonary surfactant-associated protein A (SP-A) staining and electron microscopy. PPARγ

TNF-α and SP-A mRNA levels in AT-Ⅱcells were assayed by RT-PCR after being activated by lipopolysaccharide (LPS) stimulation

while the PPARγ and TNF-α protein levels in culture supernatants were measured by Western blotting and ELISA respectively.    Results   Primary culture of rat AT-Ⅱ cells were successfully established as confirmed by the expression of AKP and SP-A and unltrastructural features. PPARγ expression in AT-Ⅱ cells were decreased when stimulated with LPS

which were accompanied by increased TNFα expression.    Conclusion   Pro-inflammatory substance LPS can markedly inhibit the expression of PPARγ in AT-Ⅱcells

which could be involved in the loss of control of inflammation.