Prostaglandin F2 alpha causes regression of the corpus luteum.
Prostaglandin F2-alpha (PGF2-alpha) causes luteolysis or regression of the corpus luteum (CL) from day 5 to 18 of the estrous cycle in animals that are cycling making it useful for estrus synchronization. PGF2-alpha also causes regression of the CL in other conditions with a persistent CL such as pyometra, mummified fetus, mucometra, and macerated fetus.
The presence of a CL on the ovary is a factor in creating a condition called pyometra or pus in the uterus. This may also result in a chronic inflammation of the uterus called endometritis. Regression of the CL is also a key event in controlling the bovine estrous cycle.
Two conditions that lead to pyometras in cattle are:
1) Metritis/clinical endometritis following calving. A small percentage of cows fail to develop a normal estrous cycle following an ovulation when an infection is present in the uterus and the corpus luteum persists resulting in a pyometra.
2) If the bulls in a herd using natural service are infected with Tritrichomonas foetus, cows may develop pyometras following services to infected bulls.
Pyometra from Tritrichomonas foetus may be prevented by testing all bulls for T. foetus prior to introduction to service, using virgin bulls and using young bulls.