The lung parenchymal strip as a sensitive assay for leukotriene B4.

Leukotriene B4 (LTB4) (3 X 10(-11) to 1.5 X 10(-9) mole; 10 ng to 500 ng) contracted the guinea-pig lung parenchymal strips in a dose-dependent manner. The contractile effect of LTB4 was not affected by methysergide (0.2 microgram/ml), propranolol (3.0 microgram/ml), phenoxybenzamine (0.1 microgram/ml), atropine (0.1 microgram/ml), diphenhydramine (0.1 microgram/ml) and FPL-55712 (1.0 microgram/ml), but was nearly completely abolished by indomethacin (20 microgram/ml). It is concluded that the contraction of the parenchymal strip to LTB4 may constitute a simple, sensitive and selective bioassay which could be either used for the determination of LTB4 in biological material or for studies on structure-activity relationship.