Glucocorticoid Mechanism of Action

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Questions and Answers

What is the most common long-term side effect of using glucocorticoids?

Cushing-like syndrome

Osteoporosis (correct)

Gastritis

Hyperglycemia

What is the main function of aldosterone in the kidneys?

To decrease sodium levels

To decrease bicarbonate levels

To increase potassium levels

To increase water and electrolytes (correct)

What is the effect of spironolactone on the body?

It increases sodium reabsorption

It stimulates aldosterone synthesis

It decreases potassium reabsorption

It competes for the mineralocorticoid receptor and inhibits sodium reabsorption (correct)

What is the use of fludrocortisone?

To treat Addison disease Signup and view all the answers

What is the effect of ketoconazole on the body?

It inhibits gonadal and adrenal steroid synthesis Signup and view all the answers

What is the benefit of using eplerenone over spironolactone?

It has less affinity for androgen receptors Signup and view all the answers

What is the primary use of glucocorticoids in asthma and COPD?

To reduce inflammation in the lungs Signup and view all the answers

Which of the following glucocorticoids is used to hasten fetal lung maturation in preterm infant delivery?

Betamethasone Signup and view all the answers

What is the primary mechanism of the dexamethasone suppression test in diagnosing Cushing syndrome?

Suppressing ACTH production to diagnose cortisol excess Signup and view all the answers

What is the primary complication of glucocorticoid deficiency in congenital adrenal hyperplasia?

Virilization of females and prepubertal males Signup and view all the answers

What is the primary function of the steroid-receptor complex in the nucleus?

To act as a transcription factor to regulate gene expression Signup and view all the answers

Which of the following glucocorticoids has the longest half-life?

Dexamethasone Signup and view all the answers

What is the primary use of glucocorticoids in inflammatory skin disorders?

To reduce inflammation and swelling Signup and view all the answers

What is the effect of glucocorticoids on muscle protein?

Muscle protein breakdown Signup and view all the answers

What is the primary mechanism of glucocorticoids' anti-inflammatory effect?

Inhibition of phospholipase A2 Signup and view all the answers

What is the effect of glucocorticoids on lymphoid tissue?

Lymphoid tissue wasting Signup and view all the answers

What is the role of coactivator or corepressor proteins in the mechanism of glucocorticoid action?

To recruit other proteins to the steroid receptor complex Signup and view all the answers

What is the effect of glucocorticoids on bone metabolism?

Osteoporosis Signup and view all the answers

What is the primary naturally occurring glucocorticosteroid?

Cortisol (hydrocortisone) Signup and view all the answers

What is the effect of glucocorticoids on cell-mediated immunologic functions?

Decreased cell-mediated immunologic functions Signup and view all the answers

Study Notes

Mechanism of Action of Glucocorticoids

Bind to steroid receptors in the cytosol, forming a steroid-receptor complex
The complex translocates to the nucleus, recruiting coactivators or corepressors, and binds to hormone response elements or gene promoter elements (GRE or MSE)
Acts as a transcription factor to turn genes on or off, depending on the tissue and complexed proteins

Effects of Glucocorticoids

Metabolic: promote gluconeogenesis, proteolysis, lipolysis, and lipogenesis, leading to net fat deposition
Catabolic: muscle protein breakdown, lymphoid, connective tissue wasting, fat and skin, and osteoporosis
Immunosuppressive: decrease cell-mediated immunologic functions, especially lymphocytes
Anti-inflammatory: inhibit phospholipase A2, increase neutrophils, and decrease chemotaxis, basophils, monocytes, eosinophils, and lymphocytes

Glucocorticosteroids

Cortisol (hydrocortisone): the major naturally occurring glucocorticosteroid
Synthetic glucocorticosteroids: prednisone, triamcinolone, dexamethasone (longest half-life), betamethasone (topical), beclomethasone, and budesonide (short half-lives)

Uses of Glucocorticosteroids

Asthma and COPD: inflammatory lung diseases
Addison disease: primary glucocorticoid insufficiency
Diagnosis of Cushing syndrome: dexamethasone suppression test
Congenital adrenal hyperplasia: deficiency of cortisol and aldosterone synthesis
Inflammatory skin disorders, allergic reactions, and urticaria
Rheumatological and autoimmune disorders, such as TMJ and RA
Blood cancers, such as lymphatic leukemia
Preterm infant delivery: hasten lung maturation prior to delivery

Side Effects of Glucocorticosteroids

Dose-related: primary dose-related side effects
Osteoporosis: most common long-term side effect
Gastritis: most common short-term side effect
Cushing-like syndrome
Hyperglycemia
Cataracts
Skin atrophy, ecchymosis, and purple striae with long-term topical use
Immunosuppression: increased infection
Inhaled: oral candidiasis, hoarseness, and throat irritation
CNS: mood changes, including swings, euphoria, and depression

Mineralocorticosteroids

Aldosterone: the major naturally occurring mineralocorticosteroid in humans
Synthetic mineralocorticosteroids: fludrocortisone (has significant glucocorticoid activity)
Corticosteroid antagonists: spironolactone and eplerenone
Antagonize mineralocorticoid receptors, inhibiting sodium reabsorption and increasing potassium reabsorption

Corticosteroid Antagonists

Spironolactone: antagonizes mineralocorticoid receptors, competes for the receptor, and inhibits sodium reabsorption and increases potassium reabsorption
Eplerenone: selective aldosterone antagonist with less affinity for androgen receptor
Uses: resistant hypertension, heart failure, hyperaldosteronism, and hirsutism in women
Adverse effects: hyperkalemia, gynecomastia, menstrual irregularities, and skin rashes

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Description

This quiz covers the mechanism of action of glucocorticoids, including their role in immunity and how they bind to steroid receptors. It's a great resource for students of pharmacology and medicine.