The PGF2α transferred from the uterus to the ovary is thought to occur either by local countercurrent transfer or general systemic transfer. Countercurrent transfer involves the movement of molecules (PGF2α) across the blood vascular system from higher concentrations in the venous effluent (utero-ovarian vein) to an area of lower concentration (ovarian artery). Systemic transfer involves the passage of the molecules through the general circulatory system.

In some species (cow and ewe), PGF2α synthesis from a uterine horn only influences the life span of the CL in the ipsilateral ovary. In other species (sow and perhaps mare), PGF2α synthesis from one horn is sufficient to cause regression of CL in both ovaries.