Unit 04: Glucocorticoids Flashcards
what part of adrenal glad producted steriod hormones?
what does it produce?
The outer portion or the adrenal cortex produces steroid hormones such as mineralocorticoids, glucocorticoids and sex steroids.
what is the genreal role of mineralocorticoids/ what is general role of glucocorticoids
- mineralocoticoids play a role in sodium and water conservation
- glucocorticoids are responsible for increasing blood glucose levels
*both syn from cholesterol that is converted to corticosteroids in the adrenal cortex
what is aldosterone?
mineralocorticoid that regulates sodium and water in the body by increasing sodium, chloride and water or decreasing potassium, phosphate and calcium
what is cortisol
glucocorticoid that is involved with glucose regulation by increasing blood glucose conc
*also has anti-inflammatory and immunosuppressive effects
what causes glucocorticoids to inhibition of immune function and inflammatory processes
Glucocorticoids indirectly block phospholipase A2 that then inhibits prostaglandin and leukotriene production.
These effects will result in inhibition of immune function and inflammatory processes.
how do glucocorticoids exert their effects?
- activation of genes whos proteins are involved in mediating inflammatory responses
- cortisol diffused thru cell mem and bidns to glucocorticoid recepto protein complex found in cytosol of msot cells
- when hormone binds it releases the protiens and activates the receptor
- the activated receptor then bidns to glucocorticoid response elements in the DNA cuasing gene activation and proteins synthesis
what is regulated by glucocorticoids
Glucocorticoids exert their effects through activation of genes whose proteins are involved in mediating inflammatory responses
- cortisol diffuses through the cell membrane where it binds to a cortisol receptor (also called glucocorticoid receptor) protein complex
When binds it releases the proteins and activates
activated receptor then binds to glucocorticoid response elements in the DNA causing gene activation and protein synthesis.
catabolic effects of glucocoticoids on various systems
he skin, cardiovascular system, blood cell production, gastrointestinal tract, musculoskeletal system, liver and reproductive system, and others are regulated by glucocorticoids
-catabolic effects on these systems can result in decreased muscle mass, thinning of the skin, osteoporosis, redistribution of fat, and antagonize the effect of vitamin D on calcium absorption.
role of glucocorticoids in glucose metabolism
glucocorticoids stimulate hepatic glucose synthesis from amino acids and lipids - elevate blood glucose
- inhibit glucose uptake by muscle and adipose tissue, stimulate fat breakdown, and mobilize amino acids from non-hepatic tissues.
- also inhibit calcium absorption, bone formation, wound healing and immune function.
diff WBC in immune system
- neutrophils are phagocytes that are recruited to sites of inflammation first (usually infection)
eosinophils combat parasites and play role in allergic responses
- lymphocytes (T, B and NK cells) are inv in reg ciral infection and antibody production
- monocytes (macrophages and dendritic cells) also serve as phagocytes and antigen presenting cells
effect of glucocorticoids on neutrophils
INC number circulating
DEC migration
DEC enzyme release
DEC oxygen radicals
DEC prostaglandins and leukotrienes
effect of glucocorticoids on eosinophils
DEC number of circulating
effect of glucocorticoids on lymphocytes (T, B and NK cells)
DEC number circulating
DEC functionality
effect of glucocorticoids on Monocytes (macrophages and dendritic cells)
- INC number Circulating
DEC chemotaxix
DEC antibacterial activity
DEC prostaglandins and leukotrienes
describe ADME of glucocorticoids
- administered and absorbed through oral, intramuscular, subcutaneous, intra-articular and topical methods
- carried in the blood bound to carrier proteins such as albumin and transcortin.
Some metabolites activated in the liver, such as cortisone to hydrocortisone and prednisone to prednisolone.
Excretion occurs in both the urine and the feces.
what can inc the likihood of adverse effects of glucocorticoids
The risk of adverse effects appears to grow with increased dosing as well as duration of therapy.
greater risk of osteoporosis fracture is correlated with increased daily dose of prednisone, likely because of the effect of glucocorticoids on calcium homeostasis
*rtying to acheive tolderable level of discomoft at lowest dose possible, not compelte releif to reduce side effects
- dosage largely dependent on specific disease or patient
