Endocrine 2 Flashcards
List the steps in conversion of cholesterol to aldosterone.
- Cholesterol
- Pregnenolone
- Progesterone
- 11-deoxycorticosterone
- Corticosterone
- 18(OH) Corticosterone
- Aldosterone
What enzyme converts cholesterol to pregnenolone in all three layers of the adrenal cortex?
Cholesterol side chain cleavage, P450scc, Desmolase, Cyp11A1
What enzyme converts pregnenolone to progesterone in the G and F?
3-beta-HSD
What enzyme converts progesterone to 11-deoxycorticosterone?
21-hydroxylase, p450c21, Cyp21A2
What enzyme converts 11-deoxycorticosterone to corticosterone?
11-hydroxylase, P450c11, Cyp11B2
What enzyme converts corticosterone to 18(OH) corticosterone?
18-hydroxylase, p450aldo, aldosterone synthase, Cyp11B2
What enzyme converts 18(OH) corticosterone to aldosterone?
18-oxidase, p450aldo, aldosterone synthase, Cyp11B2
List the steps in conversion of cholesterol to cortisol.
- Cholesterol
- Pregnenolone
- Progesterone
- 17(OH) progesterone
- 11-deoxycortisol
- Cortisol
What enzyme converts progesterone to 17(OH) progesterone?
17-hydroxylase, P450c17, Cyp17
What enzyme converts 17(OH) progesterone to 11-deoxycortisol?
21-hydroxylase, P450c21, Cyp21A2
What enzyme converts 11-deoxycortisol to cortisol?
11-hydroxylase, P450c11, Cyp11B1
List the steps in conversion of cholesterol to DHEA.
- Cholesterol
- Pregnenolone
- 17(OH) pregnenolone
- DHEA
- DHEAS or Androstendione
What enzyme converts pregnenolone to 17(OH) pregnenolone?
17-hydroxylase, p450c17, Cyp17
What enzyme converts 17(OH) pregnenolone to DHEA?
17, 20-lyase; Cyp17
What enzyme converts DHEA to DHEAS?
Sulfotransferase
What enzyme converts DHEA to androstendione?
3-beta-HSD
Describe the levels of DHEA, glucocorticoids, and mineralocorticoids in 11-hydroxylase deficiency.
- High DHEA
- No glucocorticoids
- Low aldosterone, high MR activity
Describe the symptoms of 11-hydroxylase deficiency.
- Hypertension
- Hypokalemia
- Low renin, high ANP
- Masculinization
- High ACTH
- Salt and water retention
Describe the levels of DHEA, glucocorticoids, and mineralocorticoids in 17-hydroxylase deficiency.
- Low DHEA
- No glucocorticoids
- Low aldosterone, high MR activity
Describe the symptoms of 17-hydroxylase deficiency.
- Hypertension
- Hypokalemia
- Feminization/ambiguous genitalia
- High ACTH
- Salt and water retention
Describe the levels of DHEA, glucocorticoids, and mineralocorticoids in 21-hydroxylase deficiency.
- High DHEA
- No glucocorticoids
- No mineralocorticoids
Describe the symptoms of 21-hydroxylase deficiency.
- Hypotension
- Hyperkalemia
- High renin
- Masculinization/ambiguous genitalia
- High ACTH
- Sodium loss
Which 2 hormones are released from the ARC?
- Dopamine
2. GHRH
Which 4 hormones are release from the PVN?
- AVP
- CRH
- OXY
- TRH
Which hormone is released from the SON?
- AVP
Which hormone is released from the PeVN?
- Somatostatin
Which hormone is released from the POA?
- GnRH
What are the components of the HPL axis?
H: GHRH (ARC)
P: GH (somatotropes)
L: IGF-1 (liver)
What are the components of the HPA axis?
H: CRH (PVN)
P: ACTH (corticotropes)
A: Cortisol (zona fasciculata of adrenal cortex)
What are the components of the HPT axis?
H: TRH (PVN)
P: TSH (thyrotropes)
T: T3/T4 (follicles of thyroid gland)
What are the components of the HPG axis?
H: GnRH (POA)
P: LH/FSH (gonadotropes)
G: Androgens and Estrogens (testes/ovaries)
What are the receptors of CRH and which has a higher affinity for the hormone?
CRH-R1 (higher affinity for CRH)
CRH-R2 (higher affinity for urocortin)
What are the receptors of ACTH and which has a higher affinity for the hormone?
MC1R (lower affinity)
Mc2R (higher affinity)
What are the receptors of PTH and what is bound to each?
PTH1R: binds 1-34, 1-84, PTHrP
PTH2R: binds 1-34
Broadly, what is the result of the HPL axis?
Promotion of lean body mass, increased protein, decreased adiposity, increased plasma glucose