The steroidal hormone which gives rise to corticosteroids is Progesterone. What is the main mechanism of action glucocorticoids have at a cellular level that makes them different from other drugs?
Bind to a cytoplasmic steroid receptor and enter the cell nucleus to activate DNA transcription and elicit a biological effect from altered protein synthesis
20
Glucocorticoids act on both Anti-inflammatory pathways and Immunomodulatory pathways. Which enzyme do they primarily target to elicit these effects?
Phospholipase A2
15
What are the inflammatory or immune mediators that Phospholipase gives rise to normally?
Thromboxane, Prostaglandin, Leukotrienes
20
How are glucocorticoids used to reverse ketosis in cattle?
With glucose it increases blood glucose levels by inhibiting the action of insulin, catecholamine-driven glycogenolysis in muscle and gluconeogenesis in liver
15
How do glucocorticoids initiate labour?
Mimics foetal cortisol and initiates PGF2a to begin uterine contraction and cervical dilation
15
How do glucocorticoids reduce an immune response? Which immune cells are most suppressed?
By decreasing gamma-interferon, IL-1 and 2 they decrease the activation and recruitment of T cells. This also decreases B cells, macrophage, and neutrophils
20
What would be the clinical classification of the following skin lesions?
Chronic Atopy; Atopic dermatitis
15
Mineralocorticoids are different from glucocorticoids. Why? What is their effect?
They mimic aldosterone and act to aid in renal absorption of Na/H2O and excretion of Ca, Mg, H, and K
15
What are the ONLY 2 instances you ever use corticosteroids for shock?
Provide the drug used as a mineralocorticoid in animals with Addison's disease
Fludrocortisone
15
Corticosteroids have a dose dependent action. When applying prednisolone, which animal would most likely need a higher dose (stronger effect); a dog with chronic atopy or a cat with IMHA?
A cat with IMHA. Immunosuppressive actions would require a dose that could act more systemically and on more receptors
15
Do cats need stronger or weaker doses of glucocorticoids? Why?
Stronger! They have fewer glucocorticoid receptors than dogs and need more for a clinical response
15
What can a rapid withdrawal of corticosteroids cause? (I want a clinical term)
Hypoadrenocortical crisis
20
How do you avoid a hypoadrenocortical crisis?
E.O.D dosing and lowest dose possible for therapeutic effect