Progesterones

PROGESTERONES

  • The main function of progesterone is to establish and maintain preganacy, by preparing the uterine endometrium for implantation and by preventing myometrial uterine contractions during pregnancy.
  • It also acts as a negative feed back hormone during the ovarian cycle suppressing LH and FSH secretion, oestrus and ovulation.
  • In some species, it primes behavioural centres in the brain and so allows estradiol to induce behavioural estrus.
  • It is produced mainly from the corpus luetum and the placenta and to a lesser extent from the adrenal gland.
  • In the pregnant animal, the corpus leuteum is maintained for the duration of pregnancy, except in the mare.
  • In some species such as the sow and the goat, the luteal progesterone is required throughout pregnancy: in other species such as the mare and the ewe, the placental progesterone is the primary source after day 100 in the mare and day 55 in the ewe.

Uses

  • Control of ovulation
  • Induction of ovulation
  • Reduce embryonic loss.

Synthetic progesterones

  • Medroxy progesterone (MAP) – used to control estrus and ovulation in the cyclic ewes and to induce estrus in anoestrous ewes. It can be used in bitches to suppress the onset of next estrus.
  • Flurogesterone acetate (FGA) – used to control or induce estrous in ewes.
  • Melengesterol acetate (MGA) – used to suppress estrus in heifers
  • Norgestomet – used to control or induce ovulation
  • Proligestone – used to control estrous in bitches.
Last modified: Thursday, 26 April 2012, 5:14 AM