Effect of prostaglandin D₂ (PGD₂) on bronchial smooth muscle (BSM) contractility in naive mice.

The BSM tissues isolated from naive BALB/c mice (6 animals) were incubated with PGD2 (10−5 M: closed circles) or its vehicle (PBS: open circles) for 15 minutes (A) or 24 hours (B). The BSM responsiveness to cumulatively applied acetylcholine (ACh) was measured as described in METHODS. The ACh concentration-response curve was significantly shifted upward when the BSMs were incubated with PGD2 for 24 hours (B: ***P post hoc Dunnett).