{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

18. Pregnancy Endocrinology 2010

18. Pregnancy Endocrinology 2010 - Endocrinology of...

Info icon This preview shows pages 1–16. Sign up to view the full content.

View Full Document Right Arrow Icon
Endocrinology of Pregnancy
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Gravidity - oviparous species retain egg for species specific period time defined by: – length of shelling process – oviposition timed to environmental event oviposition is under control of mother
Image of page 2
Oviparous reptiles Egg retention associated with corpus luteum activity – remove CL early in gravidity and spontaneous oviposition (e.g., lizards.snakes) at ovulation, CL formed by luteinization of granulosa and thecal cells
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
CL & Progesterone surge in progesterone observed – remains elevated in some species – others it is elevated only at ovulation
Image of page 4
Post-ovulation movement of egg down reproductive tract associated with synthesis of PGF 2 α activity present for short period period of albumen and shell fiber secretion associated with β -adrenergic stimulation oviduct contraction then becomes quiescent inhibition of β -adrenergic stimulation PG synthesis
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Oviposition I egg retention can last – a few days – or months oviposition preceded by/associated with luteolysis – PGF 2 α induces luteolysis in two lizard species
Image of page 6
Oviposition II uterine contraction associated with: 1. PGF 2 α • potent smooth muscle contractor • exogenous injection induces oviposition • elevated during natural oviposition sea turtles & tuatara – birds
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Oviposition III 2. Arginine Vasotocin (AVT) octapeptide from neurohypophysis potent smooth muscle contractor exogenous injection induces oviposition elevated during natural oviposition sea turtle & tuatara • 3. β -adrenergic stimulation blockers inhibit oviposition Lizards, birds
Image of page 8
Cervical Relaxation Relaxin - peptide hormone from CL augments timing of uterine contraction in turtle removal of CL late in gravidity inhibits oviposition in birds and reptiles - role unknown? • PGE 2 synthesis increases just prior to oviposition exogenous injection does not induce oviposition Elevated at oviposition in sea turtle, tuatara, birds
Image of page 9

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Albumen β -adrenergic Progesterone Fibers Calcium PGF 2 α Ovulation
Image of page 10
AVT Progesterone β - adrenergic PGF 2 α Estradiol Relaxin PGE 2 Oviposition
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Oviposition or nesting behavior observed in many species can be induced by PGF 2 α – fish spawning behavior – lizard oviposition behavior – pig "nesting" behavior – kangaroo belly licking behavior
Image of page 12
“Birth” Gastric brooding frog (extinct 1980s) swallow fertilized eggs embryo and tadpoles synthesize PGE 2 inhibits gastric secretion during time in stomach! Gastrotheca - marsupial frog AVT induces 'birth' - Induces female leg movements which include wiping-out the pouch
Image of page 13

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Mammalian Pregnancy viviparous eutherian mammal unlike oviparous model – pregnancy length and establishment due to embryonic signals like oviparous model – CL plays important role in many species
Image of page 14
In humans CL dies after 10-14 days unless rescued CL rescued by human chorionic gonadotropin (hCG)
Image of page 15

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 16
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern