Corpus Luteum Regression - Anatomy & Physiology

BACK TO THE OVARY BACK TO PROCESSES TAKING PLACE IN THE OVARY

• Prostaglandin F2 (PGF2)
• PGF2 from the uterus is transported to the ipsilateral ovary through a vascular counter-current exchange mechanism.
• This involves two closely associated blood vessels in which blood from one vessel flows in the opposite direction to that of the adjacent vessel.
• Low molecular weight substances in high concentrations in one vessel cross over into the adjacent vessel, where they are low in concentration.
• The ovarian artery lies in closs association with the utero-ovarian vein.
• By counter-current exchange, PGF2 is transferred across the wall of the uterine vein into the ovarian artery by passive diffusion.
• This ensures a high proportion of PGF2 produced by the uterine glands will be transported directly to the ovary and corpus luteum without dilution in the systemic circulation.
• This is an important mechanism, because much PGF2 is denatured during one pass through the circulatory system. This is about a 90% loss in the ewe and cow.