since arachidonic acid is the obligatory precursor of prostaglandins e2 and f2 alpha , currently believed to be associated with the initiation of labor , and polyunsaturated fatty acids inhibit the cell-mediated immune response in vivo , the precise role of prostaglandins and their precursors in the initiation of parturition must be critically examined .
C0012472
prostaglandins e2
C0033554
prostaglandins