Term
| Modifications from cholesterol -> steroid hormones |
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Definition
Estrogen: Ring A aromatized
Side chain at C-17 cleaved to 2 carbons(corticosteroids, progestins) or lost (androgens,estrogens)
Mineralcorticoids(Aldos) -> aldehyde group at C-18
Oxygens introduced by hydroxylation(CP450) |
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Term
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Definition
Transfer one oxygen atom to substrate and reduce other to oxygen.
Steroid-H + O2 + NADPH ->
Steroid-OH + H2O + NADP
Enzymes bound to SER but considered cytosolic
Contain heme and require CP450, NADPH, O2 |
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Term
| Rate limiting step of steroid hormone synthesis |
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Definition
Transport of cholesterol into mitochondria
StAR regulates cholesterol transport into mitochondria. |
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Term
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Definition
Abnormal sexual development, only effects males.
Can't produce Dihydroxytestosterone
Born with male gonads but have female primary sex charteristics.
DHT required for male genitalia |
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Term
| 3-β-hydroxysteroid dehydrogenase deficiency |
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Definition
Progenolone -> progesterone blocked
No glucocoritcoids, androgens
Salt wasting, female genitalia
Hyponatremia and hyperkalemia |
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Term
| 17-α-hydroxylase deficieny |
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Definition
Sex hormones and cortisol not produced
progestrone -> mineralcorticoid production
Retention of sodium and fluids -> hypertension |
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Term
| 21-α-hydroxylase deficiency |
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Definition
Most common form of CAH(95%)
High levels of ACTH due to lack of cortisol negative feedback
Maculinzation of females, early virilization of males
Salt wasting.
No glucocorticoids or mineralcorticoids |
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Term
| 11-β hydroxylase deficiency |
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Definition
Increased Androgens
Increased 11-deoxycorticosterone ->
Low renin-hypertension |
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Term
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Definition
Hypersecretion of ACTH by pituitary tumor
Obesity |
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Term
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Definition
Adrenocortical failure: insufficient production of gluco/mineralcorticoids
Hypoglycemia, Na+/K+ imbalance, dehydration,
hypotension, hyperpigmentation |
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Term
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Definition
Major activator of gluconeogenesis
Inhibits Acth production |
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Term
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Definition
Produced in response to angiotensin.
Aldosterone aises Na+ absorption into blood, increases H20 retention -> Increased BP |
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Term
| Steroid hormone receptors |
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Definition
Ligand binding to Steroid receptors hides repression domain and presents acidic activation domain.
GR and ER are homodimers, bind inverted repeats
VDR, TR, RAR, PPAR are heterodimers, bind direct repeats. |
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