Pharm Flashcards
- High during pregnancy (increased by estrogen)
- Low in liver dz (cirrhosis)
- Aka Corticosteroid Binding Globulin (CBG)
Transcortin
Main target cell type of mineralocorticoids:
2 effect on gene expression those cells:
-Principal cells of distal tubule and collecting duct.
- Increase epithelial Na+ channel (ENaC)
- Increase Na+/K+ pump
Mineralocorticoids Effects on gene expression: -NADPH reductase >> -Collagen, TGF-ß >> -IL-6, cell adhesion molecules >> -PAI-1 >>
Mineralocorticoids
Effects on gene expression:
-NADPH reductase»_space; oxidative stress
-Collagen, TGF-߻_space; fibrosis, cell senescence
-IL-6, cell adhesion molecules»_space; inflammation
-PAI-1»_space; inhibition of fibrinolysis, blood clotting
What is the transactivation mechanism of glucocorticoids?
What is the transrepression mechanism?
Transactivation mechanism of glucocorticoids: GR-ligand complex binds to GRE in gene promoters to activate gene expression
Transrepression: GR-ligand complex binds to other transcriptions factor complexes to suppress their activation of gene transcription
- NF-kB, AP-1
- Anti-inflammatory, immunosuppressive, anti-growth effects
Decreased activity of 11ß-HSD type 2 results in excessive activation of MR mediated by cortisol.
- Inhibition of this enzyme will increase activation of MR by cortisol to cause:
- 2 substances which embody this concept:
Hypertension
- Glycyrrhizin (active ingredient in licorice root extract) – increased activity of cortisol at MR»_space; increased Na+ and H2O retention»_space; increased BP
- Carbenoxolone (approved in UK to treat esophageal ulcers)
Inactivating mutations in 11ß-HSD type 2 cause AME (apparent mineralocorticoid excess) leading to: (2)
Hypertensive syndromes and edema
Placental 11ß-HSD type 2 reduces fetal exposure to maternal cortisol.
- Inhibition of the placental enzyme leads to:
- (Low/high) weight at birth
- (Increased/decreased) risk of HTN at adult age
Placental 11ß-HSD type 2 reduces fetal exposure to maternal cortisol.
- Inhibition of the placental enzyme leads to elevated levels of cortisol in fetal tissues
- Low weight at birth
- Increased risk of HTN at adult age
Effects of glucocorticoids on carb metabolism:
- Increased phosphoenolpyruvate carboxykinase»_space; (increase/decrease) gluconeogenesis
- Increased glucose-6-phosphatase»_space; (increase/decrease) glucose output into circulation
- Increased glycogen synthase in liver»_space; (increase/decrease) glycogen synthesis
- Decreased expression of GLUT4»_space; (increase/decrease) glucose uptake by muscle and adipose tissues
Effects of glucocorticoids on carb metabolism:
- Increased gluconeogenesis
- Increased glucose output into circulation
- Increased glycogen synthesis in liver
- Decreased glucose uptake by muscle and adipose tissues
Effects of glucocorticoids on lipid metabolism:
- Promote stimulation of hormone-sensitive lipase»_space; (increase/decrease) lipolysis
- (Increase/decrease) mobilization of free fatty acid and glycerol into the gluconeogenic pathway
- Increase insulin secretion»_space; (increase/decrease lipogenesis)
- Net (increase/decrease) in fat deposition
- What is the effect glucocorticoids in terms of fat distribution?
Effects of glucocorticoids on lipid metabolism:
- Increase lipolysis
- Increase mobilization of free fatty acid and glycerol into the gluconeogenic pathway
- Increase lipogenesis
- Net increase in fat deposition
- Increased fat accumulation in the upper body (shoulders, neck area, rounded face)… (thinning arms and legs due) … (adipocyte sensitivity to insulin vs. glucocorticoids varies in differnet areas of the body)
Effects of glucocorticoids on protein metabolism:
-(Increased/decreased) amino acid uptake into cells
-(Increased/decreased) protein synthesis, negative nitrogen
balance
-Mobilization of amino acids into the ___________ pathway
-Skeletal muscle – suppressed protein synthesis will lead to the development of: (2)
Effects of glucocorticoids on protein metabolism:
- Decreased amino acid uptake into cells
- Decreased protein synthesis, negative nitrogen balance
- Mobilization of amino acids into the gluconeogenic pathway
- Skeletal muscle: suppressed protein synthesis will lead to the development of myopathy and muscle wasting
Effects of glucocorticoids on immune system and inflammation:
Occur due to transrepression of NF-kB and AP-1 effects.
-Decreased phospholipase A2 and COX2»_space; (increased/decreased) production of prostaglandins and leukotrienes
-(Increased/decreased) production and increased apoptosis of immune cell types
-(Increased/decreased) production of cytokines (TNFa, IL-1, IFNg, etc.) and their receptors
-(Increased/decreased) expression of cell adhesion molecules
-(Increased/decreased) transmigration of neuts and macrophages from blood into tissues
Effects of glucocorticoids on immune system and inflammation:
Occur due to transrepression of NF-kB and AP-1 effects.
-Decreased phospholipase A2 and COX2»_space; decreased production of prostaglandins and leukotrienes
-Decreased production and increased apoptosis of immune cell types
-Decreased production of cytokines (TNFα, IL‐1, IFNg ,etc.) and their receptors
-Decreased expression of cell adhesion molecules
-Decreased transmigration of neutrophils and macrophages from blood into tissues
List a few effects of glucocorticoids on the cardiovascular system.
What are some consequences?
- Incr production of Epi and NE
- Na+/H2O retention
- Decrease in capillary permeability
- Incr HR and CO
- Incr BP
List a few effects of glucocorticoids on the GI system.
- Decr production of gastro-protective prostglandins
- Decr immune response against Helicobacter pylori
- Incr in gastric acid and pepsin secretion
List a few effects of glucocorticoids on the CNS.
- Insomnia
- Irritability
- Euphoria followed by depression
- Decr sexual libido in males
List a few effects of glucocorticoids on bone/growth.
- Decr activity of osteoblasts
- Incr activity of osteoclasts
- Decr intestinal and renal Ca2+ absorption
- Growth retardation in children
- Osteoporosis, bone fractures
List a few effects of glucocorticoids on skin.
- Decr collagen synthesis
- Decr fibroblast proliferation
- Decr wound healing, increased bruising
- Fragile and thin skin with stretch marks (“striae”)
What is the replacement therapy for adrenal insufficiency (Addison’s dz)
A combination of hydrocortisone (glucocorticoid) and fludrocortisone (mineralocorticoid).
What is the diagnostic test for Cushing’s dz?
Dexamethasone suppression test – no dexamethasone suppression of ACTH release
List a few adverse effects of mineralocorticoids (fludrocortisone)/.
- Retention of Na+/H2O, edema
- HTN
- Incr preload and cardiac enlargement»_space; CHF
- K+ loss and alkalosis
List some adverse effects of glucocorticoids.
- Immunosuppression
- Hyperglycemia
- Striae, easy bruising
- Muscle wasting, myopathy
- HTN
- Steroid-induced glaucoma
- Peptic ulcers
- Psych disorders
- Weight gain
- Osteoporosis
- Growth retardation in children
- Glucocorticoid used to treat asthma and allergic rhinitis
- Prodrug activated by esterases present in bronchial epithelial cells (local effect only, avoid systemic effects)
Ciclesonide (Alvesco)
Antagonists of adrenal corticosteroids.
- Steroid synthesis inhibitors: (4)
- Glucocorticoid antagonist: (1)
- Aldosterone antagonists: (2)
Antagonists of adrenal corticosteroids.
Steroid synthesis inhibitors
- Aminoglutethimide (Cytadren)
- Ketoconazole (Nizoral)
- Metyrapone (Metopirone)
- Mitotane (Lysodren)
Glucocorticoid antagonist
-Mifepristone (Korlym, Mifeprex)
Aldosterone antagonists
- Spironolactone (Aldactone)
- Eplerenone (Inspra)
What protein acts as the main carrier for synthetic corticosteroid drugs?
Albumin
About 80% of cortisol is metabolized by the liver. What can we then say about the half-life of cortisol in pts with liver dz’s and hypothyroid pts?
Half-life is increased (takes longer to metabolize)