Module 4 - glucocorticoids Flashcards
How do glucocorticoids differ in their molecular mechanism of action from most drugs?
Glucocorticoids differ in two ways: their receptors are located inside the cell rather than on the cell surface, and they modulate the production of regulatory proteins rather than affecting signaling pathways.
What happens when glucocorticoids penetrate the cell membrane and bind with receptors in the cytoplasm?
When glucocorticoids bind with receptors in the cytoplasm, they convert the receptor from an inactive form to an active form.
What is the next step in the molecular mechanism of glucocorticoids after the receptor becomes active in the cytoplasm?
After becoming active in the cytoplasm, the receptor-steroid complex migrates to the cell nucleus.
What does the receptor-steroid complex do in the cell nucleus?
In the cell nucleus, the receptor-steroid complex binds to chromatin in DNA, which alters the activity of target genes.
In most cases, how do glucocorticoids affect the activity of target genes?
In most cases, glucocorticoids increase the activity of target genes, leading to increased transcription of messenger RNA molecules for specific regulatory proteins.
Are there situations where glucocorticoids suppress the activity of target genes, and if so, what is the outcome?
Yes, in some cases, glucocorticoids suppress the activity of the target gene, leading to decreased synthesis of certain regulatory proteins.
How do glucocorticoids differ in their molecular mechanism of action from most drugs?
Glucocorticoids differ in two ways: their receptors are located inside the cell rather than on the cell surface, and they modulate the production of regulatory proteins rather than affecting signaling pathways.
What happens when glucocorticoids penetrate the cell membrane and bind with receptors in the cytoplasm?
When glucocorticoids bind with receptors in the cytoplasm, they convert the receptor from an inactive form to an active form.
What is the next step in the molecular mechanism of glucocorticoids after the receptor becomes active in the cytoplasm?
After becoming active in the cytoplasm, the receptor-steroid complex migrates to the cell nucleus.
What are the pharmacologic effects of glucocorticoids when administered in high doses for nonendocrine disorders?
High doses of glucocorticoids produce anti-inflammatory and immunosuppressive effects that are not seen at physiologic doses.
Are there any physiologic effects associated with high-dose glucocorticoid administration?
Yes, in addition to their pharmacologic effects, high doses of glucocorticoids also produce the physiologic effects observed at low doses.
What are the metabolic effects of high-dose glucocorticoid therapy compared to physiologic doses?
High-dose glucocorticoid therapy intensifies metabolic effects, including elevated glucose levels, suppressed protein synthesis, and increased mobilization of fat deposits.
Do most glucocorticoids have significant mineralocorticoid activity?
No, most glucocorticoids have very little mineralocorticoid activity, which generally results in limited sodium retention and potassium loss.
Is sodium retention and potassium loss completely absent with high-dose glucocorticoid therapy?
No, although most glucocorticoids have minimal mineralocorticoid activity, sodium retention and potassium loss can still occur in some patients and may pose risks.
What effect does high-dose glucocorticoid therapy have on the intestinal absorption of calcium?
High-dose glucocorticoid therapy can inhibit the intestinal absorption of calcium, an effect not observed at physiologic doses.
What are the major clinical applications of glucocorticoids primarily related to?
The major clinical applications of glucocorticoids stem from their ability to suppress immune responses and inflammation.
What are the characteristic symptoms of inflammation, and what initiates them?
The characteristic symptoms of inflammation are pain, swelling, redness, and warmth, initiated by chemical mediators such as prostaglandins, histamine, and leukotrienes.
How do prostaglandins and histamine contribute to inflammation symptoms, particularly pain and swelling?
Prostaglandins and histamine promote inflammation symptoms by causing vasodilation and increasing capillary permeability. They contribute to pain, with histamine directly stimulating pain receptors, and prostaglandins sensitizing pain receptors.
How do neutrophils and macrophages intensify inflammation, and what damage can they cause?
Neutrophils and macrophages heighten inflammation by releasing lysosomal enzymes that cause tissue injury.
What role do lymphocytes play in amplifying inflammation, and how do they do it?
Lymphocytes, crucial elements of the immune system, amplify inflammation by causing direct cell injury and promoting antibody formation, which helps perpetuate the inflammatory response.
What are the mechanisms through which glucocorticoids interrupt the inflammatory process?
Glucocorticoids interrupt inflammation through multiple mechanisms, including the inhibition of chemical mediator synthesis, suppression of phagocyte infiltration, and reduction of lymphocyte proliferation.
How do the mechanisms by which glucocorticoids suppress inflammation compare to those of nonsteroidal anti-inflammatory drugs (NSAIDs)?
The mechanisms by which glucocorticoids suppress inflammation are more diverse than those of NSAIDs, which primarily inhibit prostaglandin production. Glucocorticoids act through multiple pathways, resulting in more potent anti-inflammatory effects.
For what purpose are glucocorticoids indicated in rheumatoid arthritis?
Glucocorticoids are indicated for adjunctive treatment of acute exacerbations of rheumatoid arthritis.
What is the primary effect of glucocorticoids in rheumatoid arthritis?
Glucocorticoids can reduce inflammation and pain but do not alter the course of the disease.