Endocrine 5 (Disorders)

Question 1

Hypothalamus releases what hormones that act on what

Answer 1

Releases:
- Thyroid Releasing Hormone
- Gonadotropin Releasing Hormone

On:
- Pituitary Gland

Question 2

Growth Hormone
- Use?
- Regulation?

Answer 2

Somatropin (Recombinant GH)
- Regulated by GHRF

Treats individuals with:
- Dwarfism (Correct GH Deficiency)
- Turner’s Syndrome (Correct Growth Deficiency)
- Increase Muscle Mass

Question 3

Growth Hormone
- MOA

Answer 3

Binds to Class I Cytokine Receptor (Tyrosine Kinase Receptor)
- Stimulates growth
- Stimulates hepatic IGF production
–> Promoting uptake of amino acids and protein synthesis in skeletal muscle and cartilage of long bone

Question 4

Growth Hormone
- Adverse Effects

Answer 4

Acromegaly (Too much GH)
- Carpal Tunnel Syndrome
Cardiomegaly

Question 5

IGF
- MOA

Answer 5

IGF-1 binds to IGF-1 Receptors to activate two pathways

Ras Pathway:
- Leads to activation of Mek
–> Self-Proliferation

Akt Pathway
- Leads to activation of mTOR
–> Stimulation of Protein Synthesis

Question 6

Growth Hormone Receptor Antagonist
- MOA

Answer 6

Competitive Antagonist of GH
- Prevents GH from acting on liver receptors, preventing IGF secretion

Question 7

Growth Hormone Receptor Antagonist
- Adverse Effects

Answer 7

Elevated Liver Enzymes (Do not give to people with liver disease)

Question 8

Somatostatin Analogues
- MOA

Answer 8

Mimics action of somatostatin and inhibits Pituitary Gland
- Inhibits GH secretion

Octreotide inhibits Somatostatin Receptors 2 and 5

Question 9

Somatostatin Analogues
- Adverse Effects

Answer 9

Cardiovascular (Sinus Bradycardia)

Do not use if patient is hypoglycemic
- Somatostatin decreases different kinds of hormones, can affect alpha and beta cells

Question 10

Hormonal Replacement Therapy
- Adverse Effects

Answer 10

Does not reduce the risk coronary heart disease

Increased risk of endometrial cancer (without progesterone)

Increased risk for breast cancer (depends on duration of use)

Question 11

Testosterone
- MOA

Answer 11

Acts on Androgen Receptors (Nuclear Receptor Signalling)
- Maturation of reproductive organs
- Development of secondary sexual characteristics
- Maintenance of spermatogenesis and maturation of spermatozoa

Question 12

Testosterone
- Indication

Answer 12

Male Hypogonadism (Pituitary/Testicular Disease)

Female Hyposexuality following Ovariectomy

Question 13

Testosterone
- Adverse Effects

Answer 13

• Infertility with prolonged use (Decreased Gonadotropin Release)
• Salt and Water Retention (Edema due to effects sebaceous glands)
• Acne

Question 14

Gonadotropin Releasing Hormone Analogue
- MOA

Answer 14

Pulse Administration:
- Secretion of LH and FSH

Chronic Administration
1. Down regulation of receptors in anterior pituitary
2. Inhibition of LH and FSH
3. Suppression of testicular steroidogenesis due to decreased LH and FSH
4. Decrease in testosterone

Question 15

Gonadotropin Releasing Hormone Analogue
- Adverse Effects

Answer 15

• Transient Surge of Testosterone Secretin
• Decreased Libido

Question 16

Degarelix
- MOA

Answer 16

Reversibly binds GnRH receptor in anterior pituitary and blocks it
- Decrease LH and FSH resulting in decreased testosterone

More rapid acting
Does not cause transient testosterone surge

Question 16

Non-Steroidal Anti-Androgens
- MOA

Answer 16

Competitive Antagonist of Androgens
- Binds to androgen receptors on target tissue and inhibits androgen action
- Controls testosterone surges caused by GnRH analogues
–> Combine with GnRH analogues

Question 17

Androgen Biosynthesis Inhibitors
- MOA

Answer 17

Selectivity inhibits CYP17
- Enzyme needed for androgen biosynthesis in testicular, adrenal, and prostatic tumour tissues

Inhibition decreases androgen in prostate tissue

Question 18

Androgen Biosynthesis Inhibitors
- Adverse Effects

Answer 18

Peripheral Edema (Due to effect on mineralcorticoids)

Question 19

Alopecia and Androgens

Answer 19

Androgens stimulate hair growth on face, chest, back

Androgens inhibit hair growth on scalp
- High amounts of androgen inhibits hair growth on scalp causing male pattern baldness

Question 20

Finasteride
- MOA

Answer 20

Inhibits 5alpha-Reductase
- Prevents conversion of testosterone into the more potent dihydrotestosteron
- Treats benign prostatic hyperplasia

Question 21

Finasteride
- Adverse Effects

Answer 21

Impotence (Decreased Libido)

Question 22

Minoxidil
- MOA

Answer 22

Hair follicles convert it into Minoxidil Sulfate
- Potent vasodilator that increases blood supply to hair follicles
–> Stimulates growth of new hair follicles

Initial Hair Loss
- Old hair follicles are in stalled phase instead of growth phase
- Have to lose these old hair follicles before growth can occur

Question 23

Eflornithine
- MOA

Answer 23

Inhibits Ornithine decarboxylase in hair follicles
- Reduced cell replication
- Reduced growth of new hair follicles

May cause acne

Question 24

Prolactin
- MOA

Answer 24

Secreted by anterior pituitary by lactotroph cells (Increased during pregnancy)

Binds to single transmembrane receptor related to cytokine receptors
- Induces lactation

Inhibited by Dopamine

Question 25

Ergoline Derivatives
- MOA

Answer 25

Acts as Dopamine D2 Receptor Agonists
- Inhibits anterior pituitary from releasing prolactin
- Inhibits lactation

• Treats Hyperprolactinemia
• Treats Galactorrhea

Question 26

Ergoline Derivatives
- Adverse Effects

Answer 26

Postural Hypotension