Role in Parturition
CRH is also synthesized by the placenta and seems to determine the duration of pregnancy.
Levels rise towards the end of pregnancy just before birth and current theory suggests three roles of CRH in parturition:
- Increases levels of dehydroepiandrosterone (DHEA) directly by action on the fetal adrenal gland, and indirectly via the mother's pituitary gland. DHEA has a role in preparing for and stimulating cervical contractions.
- Increases prostaglandin availability in uteroplacental tissues. Prostaglandins activate cervical contractions.
- Prior to parturition it may have a role inhibiting contractions, through increasing cAMP levels in the myometrium.
In culture, trophoblast CRH is inhibited by progesterone, which remains high throughout pregnancy. Its release is stimultated by glucocorticoids and catecholamines, which increase prior to parturition lifting this progesterone block.
Read more about this topic: Corticotropin-releasing Hormone
Famous quotes containing the words role in and/or role:
“If women’s role in life is limited solely to housewife/mother, it clearly ends when she can no longer bear more children and the children she has borne leave home.”
—Betty Friedan (20th century)
“Whatever we’re doing, whoever we are, it isn’t enough. . . . Little wonder we have trouble finding role models to guide us through these shoals. No one less than God Herself could be all the things we’d like to be to all the people we’d like to feel approval from.”
—Melinda M. Marshall (20th century)