94. Endocrinology of pregnancy; fetoplacental endocrine unit

Question 1

Pregnancy is maintained by….

Answer 1

ovarian-, hypo- pituitary-, placental-factors

Question 2

Key hormone of pregnancy:

Answer 2

Progesterone -Progesterone is necessary in the maintenance of pregnancy -Luteal phase becomes longer (CL graviditatis) -At the beginning, ovary is the only source of progesterone, later on species can be divided into two groups 1. Species dependent on CL, dog, Cat, Goat, Swine –> Experimental ovariectomy will decrease P4 → resulting abortion 2. Species independent of CL ,Primates, Horse, Sheep, Cow. -Placenta is transformed to temporal endocrine (fetomaternal) unit: produces gestagens, etc.) -Experimental ovariectomy from 2nd trimmest will not decrease P4, no abortion!

Question 3

Placental hormones

Answer 3

1.Progesterone 2.Choriogonadotropins (hCG and eCG) 3.Placental lactogens 4.Chorionic somatomammotropin 5.P4 (in corpus luteum-independent species) 6.Placental lactogens,PL 7.Chorionic somatomammotropin (CS) (stimulates growth and lactation) 8.Estrogen (fetus-mother interaction)

Question 4

Human chorionic gonadotropin (hCG)

Answer 4

Produced in the human placenta. Role in human: -Recognition and maintanence of pregnancy -not cause abortion. -Corpus luteum stimulation (P4 production) -Role in animals (pharmacological use) -LH-like effects

Question 5

Equine chorionic gonadotropin (eCG)

Answer 5

-Equine chorionic gonadotropin (eCG; pregnant mare’s serum gonadotropin - PMSG) -gonadotropic hormone produced in the chorion of pregnant mares. Role in mare: -Production of accessory CL during pregnancy (extra Progesterone production) -Other animals :(pharmacological use) -FSH-like effects

Question 6

Fetoplacental (fetomaternal) unit

Answer 6

It means that hormone production of the placenta and steroid genesis in the fetal adrenal cortex are interdependent.

Question 7

Pregnancy Tests

Answer 7

Cow • rectal investigation; • plasma or milk progesterone by RIA, ELISA, EIA  Mare • Cubony test – chemical analysis of urine estrogens • The MIP test detects PMSG this is not a placental hormone!! Synthesis in uterine wall, transferred to serum. High serum level from day 30-40- to d 150-180; mostly FSH-like, some LH-like effect), initiates follicular development, but they are converted to CL (accessory CLs), making P4!!! • Newer tests: early pregnancy proteins (PSP-pregnancy specific protein B in swine, PAG1- pregnancy associated glycoprot-1 in cow)

Question 8

Picture

Answer 8