SM144 Hormone Mechanisms

Question 1

Characteristics of steroid hormones?

Answer 1

Small, lipophilic, not encoded by genome

Question 2

Androgen insensitivity syndrome?

Answer 2

46XY males, cells can’t sense testosterone, phenotypically female. No ovaries, internal testes.

Question 3

What is needed for tyrosine kinase receptor activity?

Answer 3

Dimerization following ligand binding

Question 4

MEN2A vs. MEN2B

Answer 4

Both forms of primary hyperthyroidism. MEN2A mutations occur in extracellular receptor domain, MEN2B occur in intracellular domain.

Question 5

Where is leptin made? What do mutations produce?

Answer 5

Adipose tissue. AR, early morbid obesity.

Question 6

JAK2 mutation?

Answer 6

Myeloproliferative dx

Question 7

How can you differentiate nephrogenic vs. central DI?

Answer 7

Water deprivation study. Normal patients will concentrate their urine, DI patients will not. If you give exogenous vasopressin and it corrects, then you know it’s central DI and not nephrogenic.

Question 8

Graves’ disease?

Answer 8

Autoimmune hyperparathyroidism. Antibodies bind TSH receptors causing constitutive activation. Unregulated production of T3/T4.

Question 9

Processing of insulin?

Answer 9

Synthesized as preproinsulin. Pre- part is the signaling peptide, cleaved off first. Pro- part is the C peptide, may have endocrine functions. Insulin is the hormone proper, made of A and B peptides.