Hormones

Question 1

Flutamide vs Faslodex?

Answer 1

Flutamide for male (Prostate), Faslodex for female (breast)

Question 2

Peptide hormones stimulate what pathways (3 examples)

Answer 2

Adenylate cyclase
RTK’s
PIP2 hydrolysis

Question 3

Lispro is the same as

Answer 3

Humalog

Question 4

Aspart is the same as

Answer 4

Novolog

Question 5

Glargine equals

Answer 5

Lantus

Question 6

Insulin signaling pathway

Answer 6

TKr phosphorylates itself and IRS
SH2 domain-containing proteins bind to receptor
PI3 Kinase activated
PK-B is activated

Question 7

Epinephrine signaling pathway

Answer 7

G Protein —-> PLC —–> PIP2 ——–> DAG + IP3 (–>Ca++) ——->PKC

(PKC phosphorylates Glycogen Synthase (OFF) and Glycogen Phosphorylase (Activates “A”)

Question 8

Glucagon acts via what pathway

Answer 8

cAMP (mediates protein kinase that phosphorylates stuff)

Question 9

Steroid carriers

Answer 9

Nonspecific = Albumin
Specific = Transcortin + SHBG

Question 10

Only ____ steroid can enter cells

Answer 10

free

Question 11

3 sources for Steroid Biosynthesis

Answer 11

• Endogenous Synthesis
• LDL
• Cholesterol esters in cells

Question 12

There are three pituitary hormones that play a role in regulating steroid biosynthesis. What are they and what do they do?

Answer 12

ACTH, LH, FSH

They activate production of:

• Synthesizing enzymes
• Cholesterol esterase
• LDL receptor

Question 13

Major regulator of Steroid biosynthesis. How is it (itself) regulated? What does it do?

Answer 13

CYP11A (Cholesterol Desmolase)

Activated by phosphorylation in mitochondria

Catalyzes C-C cleavage in a method other than hydrolysis

Question 14

Cyp21-A2 reactions (2)

Answer 14

Progesterone to Deoxycorticosterone
Deoxycorticosterone to Cortisol*

in Zona Fasiculata

Question 15

Cyp11-B2 reaction

Answer 15

makes Aldosterone

in Zona Glomerulosa

Question 16

CAH cause and effect

Answer 16

21 hydroxylase (Cyp21-A2) deficiency

Causes decreased cortisol production – more steroid shunted toward sex hormone synthesis

Question 17

Aldosterone Synthase deficiency cause and effects. What does AS normally do (biochemically)?

Answer 17

Deficient in CYP11-B2, which is required for hydroxylation of deoxycorticosterone at C-11B and C-18

Question 18

Steroid receptor domains (6)

Answer 18

• Transcription activation ( = variable & immunogenic)
• DNA binding ( = conserved)
• NLS signal
• Transcription activation subdomain
• HSP
• Steroid part?

Question 19

DNA binding domain properties

Answer 19

Two Zn+-finger motifs. One binds DNA, one dimerizes

Question 20

Cortisol suppresses inflammation via

Answer 20

Phospholipase A2 inhibition

Question 21

Steps for ACTH stimulation of cortisol synthesis

Answer 21

ACTH–receptor–Gprotein–Adenylate cyclase–cAMP

cAMP–PKA–Cholesterol release from lipoprotein–StAR protein** – Side Chain cleavage enzyme – Pregnenolone

Question 22

What is StAR protein?

Answer 22

StAR = Steroid Acute regulatory protein

Question 23

Thyroid hormone synthesis pathway

Answer 23

TGlobulin–(Tyr’s modified by iodine in colloid)–MIT/DIT —T3/T4

Question 24

What gets iodinated in Thyroid hormone synthesis? By what enzyme? Where?

Answer 24

Tyrosine residues, by Thyroid peroxidase, in the colloid

Question 25

Plasma T3 & T4 exist in free form?

Answer 25

No, bound by Thyroxin BP

Question 26

TSH acts via what kind of receptor?

Answer 26

Nuclear receptor