NO-dependent, but not TNF-–dependent, LPS-induced apoptosis was due to p53 and Bax expression.

Macrophages from control mice were treated with LPS (100 ng/mL) for the indicated periods of time. Expression of p53 was analyzed by Western blotting (A), whereas expression of Bax mRNA was analyzed by Northern blotting (B). The expression of p53 (C) and Bax (D) was analyzed in macrophages treated with either 50 μmol/L SNAP or 100 ng/mL rmTNF-α for 24 hours. Northern and Western blotting were performed as described in the “Materials and methods” section.