leukotrienes
The leukotrienes were discovered in basic studies of       arachidonic acid metabolism in leucocytes 20 years ago and were found to display        a number of biological activities which may contribute to airway obstruction.
The  @SUBJECT$  were discovered in basic studies of       arachidonic acid metabolism in leucocytes 20 years ago and were found to display        a number of biological activities which may  @PREDICAT$  to  @OBJECT$ .