Repro Drugs Flashcards
What neurotransmitters regulate GnRH neuronal firing?
GABA
NE
Dopamine
Opioids/endorphins
What stimulates GnRH release?
NE
What reduces GnRH release?
Opioids (inhibit NE release) & GABA
When does dopamine have an inhibitory effect?
Non-breeding season
What increases GnRH pulse frequency?
Estrogen POSITIVE feedback
Which hormone slows down GnRH pulse frequency?
Progesterone NEGATIVE feedback –> decr. LH
GnRH receptors are coupled to _____ receptors.
Gq
List 6 steps in GnRH receptor signaling
- Activation of phospholipase C
- Generation of IP3 & DAG
- Mobilization of intracellular Ca
- Activation of PKC
- PKC activates MAP kinase
- LH & FSH synthesis & release
What leads to GnRH/gonadotropin receptor down regulation?
continuous stimulation
Gonadorelin is a synthetic ______ analogue.
GnRH
Indication for intermittent dosing of Gonadorelin.
Infertility therapy
Indications for continuous dosing of Gonadorelin. (TQ)
Chemical castration or limit estrus
List the 4 gonadotropins.
LH
FSH
hCG
eCG
% homology between LH & hCG. (TQ)
82%
Which subunit confers specificity (TQ)?
beta
FSH & LH are ____ coupled receptors linked to ______ ________.
G-protein
adenylate cyclase –> increase cAMP
What is the gonadotrophic activity of eCG?
1ry- FSH-like
sufficient LH activity to induce ovulation & luteinization
S.E. of oxytocin use in animals
Forceful contractions of all smooth mm. –> can induce colic, etc.
PGF2-alpha acts on _______ receptors linked to ______.
Gq
IP3 & Ca activation of protein kinase C.
4 S.E.s of prostaglandin analogs.
- incr smooth mm. tone –> diarrhea, abdominal pain, bronchoCONSTRICTION, incr. BP
- Small animals- vomiting
- Retained placenta after abortion
- Abortion-if handled by pregnant women
What is the specific use of PGF2-alpha in mares?
TX mating induced persistent endometritis
MOA of progesterone analogs.
incr. suppression of LH & FSH
acts on progesterone receptors in hypothalamus & pituitary gland
All anabolic adrenal steroids are derived from _______.
Cholesterol
In high doses, what other drugs can be used to mimic the effects of anabolic steroids?
Beta 2 agonists
Clinical effects of anabolic steroids.
Increases: myelopoiesis, production of EPO, strength & vitality, appetite, protein production
Steroid receptors are _____.
Ligand-activated
Alkylated anabolic steriod with strong anabolic and weak androgenic effects.
Stanazolol
Non-alkyalating anabolic steriod
Nandrolone
4 S.E.s of Stanazolol & Nandrolone
Stanazolol - wt gain due to Na & H2O rentention
Hepatotoxic
Carcinogenicity
Teratogenicity
Why would you use synthetic compounds over natural hormones?
If the natural hormone has a short 1/2 life
