Line 57: |
Line 57: |
| | | |
| * The pig conceptus produces oestradiol as the signal for maternal recognition of pregnancy. | | * The pig conceptus produces oestradiol as the signal for maternal recognition of pregnancy. |
− | * Also, PGF2 is produced in significant quantities, but is rerouted into the uterine lumen. | + | * Also, PGF2α is produced in significant quantities, but is rerouted into the uterine lumen. |
− | * Oestradiol is produced 11-12 days after ovulation. This does not inhibit secretion of PGF2 , but causes it to be secreted in a different direction than in a cycling sow. | + | * Oestradiol is produced 11-12 days after ovulation. This does not inhibit secretion of PGF2α , but causes it to be secreted in a different direction than in a cycling sow. |
| * It is secreted away from submucosal capillaries, towards the uterine lumen. | | * It is secreted away from submucosal capillaries, towards the uterine lumen. |
− | * Luminal PGF2 has little access to the circulation, and thus cannot cause luteolysis. | + | * Luminal PGF2α has little access to the circulation, and thus cannot cause luteolysis. |
| * Production of oestradiol not only prevents luteolysis, but serves to stimulate contractions of the uterine myometrium. This ensures distribution of the conceptuses with proper spacing along the uterine horns. | | * Production of oestradiol not only prevents luteolysis, but serves to stimulate contractions of the uterine myometrium. This ensures distribution of the conceptuses with proper spacing along the uterine horns. |
| | | |
Line 67: |
Line 67: |
| * The secretion of oestradiol occurs in the period of conceptus elongation. | | * The secretion of oestradiol occurs in the period of conceptus elongation. |
| * There must be at least two conceptuses in each uterine horn for pregnancy to be maintained. | | * There must be at least two conceptuses in each uterine horn for pregnancy to be maintained. |
− | * If they are not present in one uterine horn, PGF2 will be secreted in an endocrine fashion and luteolysis will occur, thus terminating the pregnancy. | + | * If they are not present in one uterine horn, PGF2α will be secreted in an endocrine fashion and luteolysis will occur, thus terminating the pregnancy. |