Adrenals

Anatomy

100

Adrenals play an important role in: 

Response to stress by regulating: 

* BP

* HR
* electrolyte balance

* BG

200

The adrenal cortex produces: 

* Aldosterone / mineralcorticoid (zona granulosa)

* Cortisol (zona fasciculata / reticularis) 

300

The adrenal medulla produces: 

epinephrine 

400

How can cortisol effect the body? 

* Liver: ↑ glycogen stores (increases BG)

* Muscle: ↑ protein catabolism (muscle wasting)

* Bone: Osteopenia 

* Skin: ↑ protein catabolism (thin skin)

* Adipose Tissue: ↑ Lipidosis (Lipemic serum)

* Blood: Stress leukogram

* Immune system: ↓ response (↑ chance of developing UTI or skin infections) 

* Kidney: ↓ GFR, PU, ↑ Ca excretion 

500

Explain how the body releases cortisol to correct BG: 

1. Brain senses low BG, pituitary releases ACTH

2. ACTH released into blood stream and attaches to adrenal cortex and stimulate cortisol release

3. Cortisol stimulates conversion of protein and fat into glucose (in liver) 

HAC

100

Aldosterone is responsible for: 

* reabsorption of Na

* excretion of K

* handling stress

* Urine concentration 

200

1. Pituitary- dependent HAC is caused by:

2. Does this respond to negative feedback? 

1. pituitary tumor that over produces ACTH

2. No

300

1. Adrenal neoplasia HAC is caused by: 

2. How do the adrenal look in these patients?

3. Does it respond to negative feedback? 

1. tumor on adrenal cortex over producing cortisol 

2. One enlarged adrenal

3. No

(Adrenal tumors do not respond to dex or ACTH stimulation, pituitary will respond to ACTH) 

400

1. Iatrogenic HAC is caused by:

2. How do the adrenals look in these patients? 

3. What is the effect of immediately stopping steroids?

1. Long term administration of steroids

2. Both adrenal atrophy (small) 

3. Signs of HAC, but stim/depress tests look like Addison's

500

What are secondary concerns of HAC? 

* DM

* Hypertension (↑ BP)

* Liver disease

* Immunosuppression (↑ chance of UTI/ skin infection)

* Muscle loss

HAC and BW

100

What do you expect to see on CBC on patients with HAC? 

Lipemic serum/ plasma

Stress leukogram 

200

What do you expect to see on chemistry profile in HAC patients? 

* ↑ ALP (remember: this is also ↑ by steroids)

* ↑ AST/ ALT 

* ↑ Cholesterol 

* ↑ Glu

* ↓ BUN/ Creat

300

What do you expect to see on a u/a on a patient with HAC? How?

* Hyposthenuric (1.008 - 1.012)

Cortisol inhibits ADH 

400

What is a screening test you can perform to determine if your patient has HAC? 

Urine Cortisol/ Creatinine Ratio

(REMEMBER: Can have false positives. If the patient is stressed this can alter results)

(If the results are negative/ normal then we can confidently say this patient does NOT have HAC) 

500

How do HAC usually present? 

* Pot-bellied

* Thin skin

* Alopecia

* Panting

* Lethargy 

Testing/ other animals

100

What are the main pros and cons of using ACTH stim test to DX HAC? 

Pros: more specific than LDDS, can DX iatrogenic HAC

Cons: Less sensitive than LDDS (not confident in positives), cannot differentiate pituitary vs adrenal neoplasia 

200

1. When performing a LDDS, a healthy animal will:

2. With HAC the cortisol levels will: 

3. With pituitary HAC, cortisol levels will: 

1. suppress blood cortisol by 50% in 6-8 hours

2. Not decrease 

3. Not decrease (will not ↑ with ACTH either)

(So pituitary will not respond to LDDS or ACTH)  

300

1. What is the main reason a HDDS is performed? 

2. Patients with pituitary HAC will: 

3. Patients with adrenal HAC will:

1. Differentiate pituitary vs adrenals

2.  suppress ACTH 

3. NOT suppress cortisol 

400

Ferrets can have issues with adrenals due to high levels of ________. 

estrogen

500

Define hirsutism (in horses): 

What disease is this typically seen with? 

A long, shaggy coat that fails to shed normally, sometimes appearing curly. This is due to a prolonged hair growth cycle caused by hormonal imbalances.

PPID 

Addison's

100

1. Define Primary Addison's:

2. Define Secondary (Atypical) Addison's: 

1. ↓ Aldosterone production and cortisol 

2. Can not produce cortisol 

200

What do you expect to see on BW and u/a of a patient with Addison's?

CBC: They will NEVER have stress leukogram

CHEM: ↑Na, ↓K, ↓Glu, azotemia (only during crisis)

U/A: ↓USG, azotemia 

300

1. What is the best test for Addison's?

2. What will the results look like if the patient has Addison's? 

1. ACTH stim test

2. No response 

400

Define Pheochromocytoma: 

cancer of adrenal medullar over producing epi

500

What is the treatment for HAC? 

Trilostane (Vetoryl)