Endo - Physiology (Signaling Pathways)

Question 1

Which 12 endocrine hormones signal via cAMP?

Answer 1

(1) FSH (2) LH (3) ACTH (4) TSH (5) CRH (6) hCG (7) ADH (V2-receptor) (8) MSH (9) PTH (10) calcitonin (11) GHRH (12) glucagon; Think: “FLAT ChAMP”

Question 2

Which 2 endocrine hormones signal via cGMP? What do these have in common?

Answer 2

(1) ANP (2) NO (EDRF); Think vasodilators

Question 3

What are 7 endocrine hormones that signal via IP3?

Answer 3

(1) GnRH (2) Oxytocin (3) ADH (V1-receptor) (4) TRH (5) Histamine (H1-receptor) (5) Angiotensin II (6) Gastrin; Think: “GOAT HAG”

Question 4

What are 7 endocrine hormones that signal via steroid receptor?

Answer 4

(1) Vitamin D (2) Estrogen (3) Testosterone (4) T3/T4 (5) Cortisol (6) Aldosterone (7) Progesterone; Think: “VETTT CAP”

Question 5

What are 5 endocrine hormones that signal via intrinsic tyrosine receptor? With what pathway are these associated? What do these have in common?

Answer 5

(1) Insulin (2) IFG-1 (3) FGF (4) PDGF (5) EGF; MAP Kinase pathway, Think growth factors

Question 6

What are 3 endocrine hormones that signal via receptor-associated tyrosine kinase? With what pathway are these associated? What do these have in common?

Answer 6

(1) Prolactin (2) Immunomodulators (e.g., cytokines IL-2, IL-6, IL-8, IFN) (3) GH; JAK/STAT pathway; Think acidophiles and cytokines; Think: “PIG”

Question 7

What significant property do steroid hormones have? As a result, how are they circulated, and what effect does this have on their solubility?

Answer 7

Steroid hormones are lipophilic and therefore must circulate bound to specific binding globulins, which increases their solubility

Question 8

What effect does high SBHG have in men, and why?

Answer 8

In men, high sex hormone-binding globulin (SHBG) lowers free testosterone => gynecomastia

Question 9

What effect does low SBHG have in women, and why?

Answer 9

In women, low SHBG raises free testosterone => hirsutism

Question 10

What effects do OCPs have on SBHG and estrogen levels? What condition has the same effects?

Answer 10

OCPs, pregnancy increase SHBG (free estrogen levels remain unchanged).

Question 11

What steps occur following hormone entering a cell?

Answer 11

(1) Binding to receptor located in nucleus or cytoplasm (2) Transformation of receptor to expose DNA-binding domain (3) Binding to enchancer-like element in DNA (4) Gene => Pre-mRNA => mRNA => Protein => Response