Endometrial cup
| Endometrial Cups | |
|---|---|
| Anatomical terminology |
Endometrial cups form during pregnancy in mares and are the source of equine chorionic gonadotropin (eCG) and a placenta-associated structure, which is derived from the fetus. Their purpose is to increase the immunological tolerance of the mare in order to protect the developing foal.
Function
Endometrial cups are unique to animals in the horse family, and so named because of their concave shape.[1] They are a placenta-associated structure,[2] found in the uterine wall of a mare from about 38 to 150 days into a pregnancy. After about 70 days, they begin to regress,[3] and are eventually destroyed by the immune system.[2] They can vary in shape but have clear raised edges and are, at most, about 5 x 2.5 x. 2.5 cm in size. They resemble ulcers in form, and when examined under a microscope have large epithelioid decidual-like cells and large nucleoli.[3]
They produce high concentrations of equine chorionic gonadotropin (eCG), also called pregnant mare's serum gonadotropin, in the bloodstream of pregnant mares. eCG is actually an equine luteinizing hormone.[2] Endometrial cups behave somewhat like cells from metastatic tumors, in that they leave the placenta and migrate into the uterus. Their purpose appears to be to work with other placental cells to control the expression of histocompatibility genes so that the developing fetus is not destroyed by the mare’s immune system.[1]
Similar types of cells that invade the placenta have been described in humans. The purpose of these cells In both humans and horses is believed to be to interact with the mother’s immune system and increase maternal immunological tolerance of the developing fetus.[1]
See also
References
- ^ a b c "Endometrial Cups". Cornell University. June 20, 2014. Retrieved April 17, 2016.
- ^ a b c "Endometrial Cups and Secretion of Equine Chorionic Gonadotropin". Colorado State University. Retrieved 17 April 2016.
- ^ a b Jacobs, PH; Elsinghorst, TA (1 April 1987). "[Endometrial cups in horses]". Tijdschrift voor diergeneeskunde. 112 (7): 383–9. PMID 3576577.