Recombinant feline (a) and human (b) FP receptors: formation of [3H]-inositol phosphates in response to 17-phenyl PGF2α, PGF2α 1-OH, and PGF2α 1-OCH3. Points represent mean values±s.e.mean. (a) feline: 17-phenyl PGF2α n=3, PGF2α 1-OH n=4, PGF2α 1-OCH3 n=3 experiment performed in duplicate. (b) human: 17-phenyl PGF2α n=6, PGF2α 1-OH n=3, PGF2α 1-OCH3 n=3 experiment performed in duplicate.