Repro Drugs

Question 1

What neurotransmitters regulate GnRH neuronal firing?

Answer 1

GABA
NE
Dopamine
Opioids/endorphins

Question 2

What stimulates GnRH release?

Answer 2

NE

Question 3

What reduces GnRH release?

Answer 3

Opioids (inhibit NE release) & GABA

Question 4

When does dopamine have an inhibitory effect?

Answer 4

Non-breeding season

Question 5

What increases GnRH pulse frequency?

Answer 5

Estrogen POSITIVE feedback

Question 6

Which hormone slows down GnRH pulse frequency?

Answer 6

Progesterone NEGATIVE feedback –> decr. LH

Question 7

GnRH receptors are coupled to _____ receptors.

Answer 7

Gq

Question 8

List 6 steps in GnRH receptor signaling

Answer 8

1. Activation of phospholipase C
2. Generation of IP3 & DAG
3. Mobilization of intracellular Ca
4. Activation of PKC
5. PKC activates MAP kinase
6. LH & FSH synthesis & release

Question 9

What leads to GnRH/gonadotropin receptor down regulation?

Answer 9

continuous stimulation

Question 10

Gonadorelin is a synthetic ______ analogue.

Answer 10

GnRH

Question 11

Indication for intermittent dosing of Gonadorelin.

Answer 11

Infertility therapy

Question 12

Indications for continuous dosing of Gonadorelin. (TQ)

Answer 12

Chemical castration or limit estrus

Question 13

List the 4 gonadotropins.

Answer 13

LH
FSH
hCG
eCG

Question 14

% homology between LH & hCG. (TQ)

Answer 14

82%

Question 15

Which subunit confers specificity (TQ)?

Answer 15

beta

Question 16

FSH & LH are ____ coupled receptors linked to ______ ________.

Answer 16

G-protein

adenylate cyclase –> increase cAMP

Question 17

What is the gonadotrophic activity of eCG?

Answer 17

1ry- FSH-like

sufficient LH activity to induce ovulation & luteinization

Question 18

S.E. of oxytocin use in animals

Answer 18

Forceful contractions of all smooth mm. –> can induce colic, etc.

Question 19

PGF2-alpha acts on _______ receptors linked to ______.

Answer 19

Gq

IP3 & Ca activation of protein kinase C.

Question 20

4 S.E.s of prostaglandin analogs.

Answer 20

1. incr smooth mm. tone –> diarrhea, abdominal pain, bronchoCONSTRICTION, incr. BP
2. Small animals- vomiting
3. Retained placenta after abortion
4. Abortion-if handled by pregnant women

Question 21

What is the specific use of PGF2-alpha in mares?

Answer 21

TX mating induced persistent endometritis

Question 22

MOA of progesterone analogs.

Answer 22

incr. suppression of LH & FSH

acts on progesterone receptors in hypothalamus & pituitary gland

Question 23

All anabolic adrenal steroids are derived from _______.

Answer 23

Cholesterol

Question 24

In high doses, what other drugs can be used to mimic the effects of anabolic steroids?

Answer 24

Beta 2 agonists

Question 25

Clinical effects of anabolic steroids.

Answer 25

Increases: myelopoiesis, production of EPO, strength & vitality, appetite, protein production

Question 26

Steroid receptors are _____.

Answer 26

Ligand-activated

Question 27

Alkylated anabolic steriod with strong anabolic and weak androgenic effects.

Answer 27

Stanazolol

Question 28

Non-alkyalating anabolic steriod

Answer 28

Nandrolone

Question 29

4 S.E.s of Stanazolol & Nandrolone

Answer 29

Stanazolol - wt gain due to Na & H2O rentention
Hepatotoxic
Carcinogenicity
Teratogenicity

Question 30

Why would you use synthetic compounds over natural hormones?

Answer 30

If the natural hormone has a short 1/2 life