Lecture 2 - Reproductive Endocrinology

Question 1

Hormone

Answer 1

a substance produced by glands that is transported by the blood to exert a specific effect upon another organ

Question 2

4 chemical classes of reproductive hormones

Answer 2

1. peptides
2. glycoprotein
3. steroids
4. prostaglandins

Question 3

Peptides

Answer 3

• repro hormone
• aa building blocks connected by peptide bonds
• Gonadotropin Releasing Hormone (GnRH)
• small and easy to be degraded

Question 4

Glycoprotein

Answer 4

• repro hormone
• 2 protein units: alpha subunit which is common among hormones and beta subunit which is unique for each hormone
• complex and specific
• need ALL components to interact with receptors and be recognized

Question 5

Steroids

Answer 5

• repro hormone
• lipid of origin: cholesterol
• enzymatic conversions convert cholesterol into a steroid via a pathway

Question 6

Steroid pathwya

Answer 6

Cholesterol
Pregnenolone
Progesterone
Testosterone
Estradiol

Question 7

Prostaglandins

Answer 7

• repro hormone
• PFG2aplha and PGE2

Question 8

Hydrophobic - lipid hormones

Answer 8

-steroids and prostaglandins
-needs carrier proteins in blood
-pass right through cell membrane to ceptors inside

Question 9

Hydrophilic - protein hormones

Answer 9

-peptides and glycoproteins
-free in blood
-plasma membrane bound receptors

Question 10

Steps of action for protein hormones

Answer 10

1. hormone receptor binding
2. G protein activation
3. adenylate cyclase activation
4. protein kinase activation
5. synthesis of new product

Question 11

Steroid hormone action

Answer 11

1. steroid transport- piggy back onto carrier proteins
2. movement through the cell membrane, cytoplasm, and nuclear membrane
3. binding of steroid to nuclear receptor
4. mRNA and protein synthesis

Question 12

5 sources of repro hormones

Answer 12

1. hypothalamus
2. pituitary
3. gonads
4. uterus
5. placenta

Question 13

Gonadotropin Releasing Hormone (GnRH)

Answer 13

Class: neuropeptide
Target: anterior pit
Action: FSH and LH release

Question 14

FSH

Answer 14

Class: glycoprotein
Target: sertoli cells in testis, granulosa cells in ovary
Action: sertoli fxn (male), follicle growth and E2 synthesis

Question 15

LH

Answer 15

Class: glycoprotein
Target: leydig cells of testis, theca & luteal cells of ovary
Action: testosterone syn (male), ovulation and progesterone syn (females)

Question 16

Prolactin

Answer 16

Class: protein
Target: mammary glands
Action: lactation and maternal behaviour

Question 17

Hormone released from the anterior pituitary

Answer 17

1. FSH
2. LH
3. Prolactin

Question 18

Oxytocin

Answer 18

Class: neuropeptide
Target: testicular tissue, uterus and mammary
Action: sperm transport; uterine contractions and mammary cell growth

Question 19

Herring bodies

Answer 19

store oxytocin in postier pituitary until release dictated by hypothalamus

Question 20

Two cell types of anterior pituitary

Answer 20

1. Gonadotroph cells = FSH and LH produced
2. Lactotroph cells = prolactin produced

Question 21

2 ovary hormones

Answer 21

E2 and P4

Question 22

Estradiol

Answer 22

class: steroid
target: hypothalamus, repro tract, mammary gland
action: increase sexual behaviour, GnRH production and uterine activity as well as mammary development

Question 23

Progesterone

Answer 23

class: steroid
target: hypothalamus, uterine endothelium, myometrium, mammary gland
action: pregnancy maintenance = decrease sexual behaviour, GnRH production, and uterine activitity; lactation

Question 24

Testosterone

Answer 24

class: steroid
target: hypothalamus, repro tract, muscle
action: male sexuality! increase sexual behaviour and muscle development, decrease GnRH, spermatogenesis

Question 25

2 hormones produced in the uterus

Answer 25

Prostaglandin E2 and Prostaglandin F2alpha

Question 26

Prostaglandin E2

Answer 26

class: prostaglandin
target: ovary
action: increase progesterone production

Question 27

Prostaglandin F2alpha

Answer 27

class: prostaglandin
target: ovary, uterine myometrium
action: decrease progesterone production, uterine contractions

Question 28

Hormone produced in placents

Answer 28

Progesterone (some species) and Equine chorionic gonadotrophin

Question 29

Progesteron

Answer 29

class: steroid
target: hypothalamus, uterine endothelium & myometrium, mammary gland
Action: pregnancy maintence! decrease sexyal behaviour, GnRH production, uterine activity; lactation

Question 30

Equine chorionic gonadotropin

Answer 30

class: glycoprotein
target: ovary
action: maintains progesterone production

Question 31

Pineal gland

Answer 31

• above the hypothalamus btw hemispheres of the brain
• sensitive to environmental light and change in photoperiod
• releases melatonin in response to dark = regulates breeding activitiy in seasonal breeders (ex. sheep, goals, horses)