6,9-deepoxy-6,9-(phenylimino)-delta 6,8-Prostaglandin I1, (U-60,257) stimulates prostaglandin D2 and inhibits thromboxane B2 release from ionophore challenged human dispersed lung cells.

6,9-deepoxy- 6,9-(phenylimino)-delta 6,8-Prostaglandin I1 (U-60,257), a prostaglandin analogue known to inhibit leukotriene formation in a number of cell systems, potentiates mast cell release of prostaglandin D2 from human dispersed lung cells activated with ionophore A23187. Over the same concentration range of 30-300 microM there was a related inhibition of ionophore-induced generation of thromboxane B2 (r = 0.93, P less than 0.01). As both prostaglandin D2 and thromboxane A2 are potent bronchoconstrictors, these observations may be relevant to the potential of this drug in the treatment of asthma.