Potential synergism between platelet-activating factor and α1-recombinant interferon in promoting luteal maintenance in cyclic ewes

In sheep, the presence of an embryo in utero on the 12th to 13th day after oestrus prevents luteolysis. These studies investigated whether platelet-activating factor (PAF) could exert an antiluteolytic function, either alone or in combination with interferon. The intrauterine administration of 250 μg PAF per horn per day, administered through indwelling cannulae into the uterus as injections twice a day (n=12) or by continuous infusion (n=4) failed to extend luteal function compared with controls (n=8)