Lectures 34-35: Pharmacology of Glucocorticoids and Mineralocorticoids | Quizlet

What are the 2 types of corticosteroilds?

Glucocorticoids

Mineralocorticoids

What secretes aldosterone?

zona glomerulosa of adrenal cortex

What secretes cortisol?

Zona fasciculata of the adrenal cortex

What secretes DHEA?

zona reticularis of the adrenal cortex

List the layers of the adrenal cortex from outermost to innermost

Glomerulosa

Fasciculata

Reticularis

Describe the mechanism of the HPA axis

Hypothalamus releases corticotropic releasing hormone which stimulates the anterior pituitary to release ACTH

ACTH then acts on the adrenal cortex to produce glucocorticoids

What are the characteristic modes of regulation of the HPA axis?

Basal steroidogenesis (diurnal rhythm)

Negative feedback regulation by adrenal corticosteroids

Stress

Glucocorticoid levels peak at what time of day?

about 8 am

The HPA axis is a ____________ feedback loop.

negative

How does stress increase corticosteroid production?

it overcomes the negative feedback regulation

What 2 steroids are released by the adrenal cortex?

Androgens

Corticosteroids

What is the purpose of corticosteroids in the body?

Allow capacity to resist stressful circumstances

Glucorticosteroids

class of steroid hormones that bind to the glucocorticoid receptor and regulates glucose metabolism, its synthesis in the adrenal cortex, and steroid structure

What are the general uses for glucocorticoids?

used to treat diseases caused by an overactive immune system

EXAMPLES:

Allergies

Asthma

Autoimmune diseases

Sepsis

Cancer (in high doses)

What is the most important human glucocorticoid?

cortisol (hydrocortisone)

Glucocorticoid effects can be classified into what two categories?

Immunologic

Metabolic

What are the immunologic effects of glucocorticoids?

increase anti-inflammatory proteins

decrease pro-inflammatory proteins

What are the metabolic effects of glucocorticoids?

Increases blood sugar levels (gluconeogensis)

Inhibits uptake of glucose into cells

Stimulates fat breakdown

What is the action of mineralcorticoids?

Active sodium reabsorption

Passive water reabsorption

Active secretion of potassium and protons

- all to increase blood pressure and volume

What is the primary endogenous mineralcorticoid?

Aldosterone

What are the minerals that mineralcorticoids regulate?

Sodium and potassium

Where is the major target of aldosterone? What does it do

acts on the distal tubule of kidney to stimulate exchange of sodium and potassium

What are the two categories of toxic effects of adrenocortical steroids?

Withdrawal (HPA axis suppression)

Supraphysiological doses

When does withdrawal occur?

rapid withdrawal of corticosteroids after prolonged therapy

What are the S/Sx of corticosteroid withdrawal?

Fever

Myalgia

Arthalgia

Malaise

Pseudotumor cerebri

What occurs when glucocorticoids are continued at supraphysiological doses?

Fluid and electrolyte abnormalities

HTN

Hyperglycemia

Increased risk of infection

Osteoporosis/ osteonecrosis

Myopathy

Behavioral disturbances

Cataracts

Peptic ulcers

When are glucocorticoids used therapeutically?

replacement therapy in deficiency

Allergic disease

Bronchial asthma

GI diseases

Why should intermediate acting steroids be given in the morning?

to diminish HPA axis suppression by following the normal diurnal rhythm

Which steroid can be used in GI diseases? Why?

Budesonide - quickly inactivated by hepatic metabolism

Glucocorticoids

Cortisol (Hydrocortisone)

Prednisone

Prednisolone

Triamcinolone

Methylprednisolone

Dexamethasone

Mineralcorticoids

Fludrocortisone

Aldosterone