Lecture 4 part 2

Question 1

Effects of GH hypersecretion Gigantism or Acromegaly

Answer 1

Acromegaly / Gigantism is a very rare disease (annual incidence: 3/1.000.000)
Gigantism results from increased GH secretion during childhood
Acromegaly results from overproduction of GH after puberty in adults
At puberty, the epiphyseal plates of the long bones close, so they become unresponsive to GH stimulation, However, this is not the case of the hands, feet, skull and lower jaw; they continue to grow, resulting in the distinctive physical appearance of an acromegaly patients

Question 2

Other hormones besides growth hormone are essential for normal growth

Answer 2

• Thyroid hormone
• Insulin
• Androgens
• Estrogens

Question 3

Thyroid hormone

Answer 3

(permissive role in skeletal growth)
Growth severely stunted in hypothyroid children
Hypersecretion does not cause excessive growth

Question 4

Insulin

Answer 4

Deficiency often blocks growth
Hyperinsulinism often spurs excessive growth

Question 5

Androgens

Answer 5

(synergistical role)
Play role in pubertal growth spurt, stimulate protein synthesis in many organs
Effects depend on presence of GH

Question 6

Estrogens

Answer 6

Effects of estrogen on growth prior to bone maturation are not well understood

Question 7

Growth hormone in a bottle - Genetic engineering

Answer 7

GH treatment appropriate for:
GH-deficient children
Adults with pituitary tumor or disease that causes GH deficiency
AIDS patients

Elderly
Decreased muscle mass
Increased fat deposition
Reduced bone density
Thinner sagging skin

Question 8

Harmful side effects from GH therapy

Answer 8

Diabetes
High blood pressure and headaches
Joint pain
Carpal tunnel syndrome
Increase risk of cancer?

Question 9

At 18 years of age and 8 feet tall, Anthony was diagnosed with gigantism caused by a pituitary tumor. The condition was treated by surgically removing his pituitary gland. What hormonal replacement therapy would he need?

Answer 9

ACTH, TSH, GH, LH, FSH
Not prolactin - he’s a man

Question 10

Why would males with testicular feminizing syndrome be unusually tall?

Answer 10

Mutations alters protein sequence of receptor
Androgen receptors are nonfunctional in male fetus
- testosterone closes ephiphysis plate
if none present, GH isn’t stopped

Question 11