MK - Endocrine Pharmacology

Question 1

What are 4 facts about the pituitary gland?

Answer 1

• The anterior and posterior pituitary have different embryological origins
• The pituitary stalk contains a portal blood supply
• The release of hormones from the anterior pituitary is controlled by releasing factors
• There is a region in the pituitary called the intermediate lobe

Question 2

How does the hypothalamus signal to the anterior pituitary and to the tissues? (3)

Answer 2

1) Hypothalamus → Anterior pituitary

• Signalled by releasing factors

2) Anterior pituitary→ Organ

• Stimulating hormone

3) Organ → Tissue

Question 3

How is negative feedback involved in this signalling pathway?

Answer 3

Release of hormone inhibits anterior pituitary from releasing more hormone

Question 4

What are some examples of releasing factors and the hormones they produce? (4)

Answer 4

• GHRF → GH (growth hormone)
• TRH → TSH (Thyroid-stimulating hormone)
• CRF → ACTH (Cortisol)
• GnRH → FSH + LH (Sex hormones)

Question 5

What do dopamine and somatostatin do?

Answer 5

• Dopamine inhibits prolactin release
• Somatostatin inhibits GH release

Question 6

What are some names of cells of the anterior pituitary? (4)

Answer 6

• Lactotrophs
• Somatrophs
• Corticotrophs
• Gonadotrophs

Question 7

What are 2 the main hormones released by the posterior pituitary, and what are their functions?

Answer 7

1) Oxytocin

• Uterine smooth muscle contraction
• Breast myoepithelial contraction

2) Vasopressin Antidiuretic Hormone (ADH)

• retention by the kidney

Question 8

What are 3 functions of the growth hormone (GH)?

Answer 8

• Stimulates amino acid/protein uptake into muscle
• Promote the utilization of fat rather than carbohydrates
• GH inhibits glucose uptake in adipose tissue

Question 9

What other growth factor does GH stimulate the release of?

Answer 9

Stimulates IGF-1 (insulin-like growth factor-1) release from liver

Question 10

What is IGF-1 and what does it aid?

Answer 10

IGF-1 is a somatomedin

• IGF-1 is especially important in the growth of skeleton and cartilage

Question 11

What does GH excess cause in childhood and in adulthood?

Answer 11

In childhood: Altered growth/stature

In adulthood: ↑GH Acromegaly

Question 12

Can somatostatin be used in acromegaly treatment?

Answer 12

Unsuitable for treatment due to short half life

Question 13

How is acromegaly treated?

Answer 13

Somatostatin receptor agonists e.g Octreozztide

• These are selective for somatostatin receptor subtypes expressed in GH-secreting tumours and have a longer half-life than somatostatin

Question 14

What are 3 treatments to GH insuffieciency?

Answer 14

1. Sermorelin is a GHRF analogue- used as a diagnostic and also to increase growth in children
2. Injection of human recombinant GH (Somatropin)
3. Injection of human recombinant IGF-(Mecasermin) –abnormal GH receptor Laron’s dwarfism