[PART 3] [ADRENAL GLAND] Clinical Chemistry [RODRIGUEZ]

major site of production of the steroid hormones

Adrenal cortex

pyramid-like shaped gland located above the kidney

Adrenal gland

Adrenal gland is compose of 2 parts which are?

adrenal cortex and adrenal medulla

Adrenal cortex contains?

lipid droplets (esterified; cholesterol-rich)

releases free cholesterol from the lipid droplets

cholesterol hydrolase

used as precursor

free cholesterol

3 layers of adrenal cortex

1. zona glomerulosa

2. zona fasciculata

3. zona reticularis

zona glomerulosa contains _________% of ____________________________.

10% mineralocorticoid (Aldosterone)

for electrolyte and water imbalances

mineralocorticoid

zona fasciculata contains _________% of ____________________________.

75% glucocorticoid & unsulfated DHEA

zona reticularis contains _________% of ____________________________.

15% dehydroepiandrosterone-sulfate and androstenedione

a weak androgen

dehydroepiandrosterone (DHEA)

a hyperglycemic agent

a hyperglycemic agent made by thyroid gland

principal glucocorticoid

cortisol

Cortisol synthesis is regulated

ACTH

positive mechanism

cortisol yung tataas so definitly mababa si ACTH kasi enough na yung cortisol para di na mas lalong dumami pa

negative mechanism

ACTH yung tataas in response sa low cortisol

Cortisol stimulates what glucose process?

gluconeogenesis

cortisol highest at

8:00 to 10:00 am

cortisol lowest at

10:00 to 12:00 mn

specimen for cortisol

-serum (red top)

-urine

blood sample should be drawn at

Serum - 8 am (kasi highest dun diba)

Urine - 24-hour urine collection

Reference value: for cortisol

: 5-25 ug/dL at 8 am to 10am

CORTISOL URINARY METABOLITES

17- hydrocorticosteroid uses what method?

Porter-Silber Method

CORTISOL URINARY METABOLITES

17- hydrocorticosteroid uses what reagent?

Phenyl hydrazine in H2SO4 + alcohol

CORTISOL URINARY METABOLITES

17- hydrocorticosteroid shows what color?

yellow color

CORTISOL URINARY METABOLITES

17-ketogenic steroids uses what method?

Zimmermann Reaction

CORTISOL URINARY METABOLITES

17-ketogenic steroids uses what REAGENT?

Meta-dinitrobenzene

CORTISOL URINARY METABOLITES

17-ketogenic steroids Oxidation procedure?

Norymberski (Na+ bismuthate)

CLINICAL TESTS

aka corsyntropin stimulation test

ACTH Stimulation Test

aka corsyntropin stimulation test

ACTH Stimulation Test

synthetic cortisol and aldosterone stimulator

corsyntropin

differentiates secondary adrenal insufficiency from tertiary adrenal insufficiency

ACTH Stimulation Test

ACTH Stimulation Test what type of blood collection?

random blood collection

Gold standard for secondary and tertiary hypocorticolism

nsulin Tolerance Test

in Insulin Tolerance Test what are minutes of collection

15, 30, 45, 60, 90, 120 mins

alternative diagnostic or confirmatory test for secondary or tertiary adrenal insufficiency

Overnight Metyrapone Tes

CUSHING'S SYNDROME is known as?

HYPERCORTICOLISM

excessive production of cortisol and ACTH but decreased aldosterone and renin

Hypercorticolism

3 Screening Test for Hypercorticolism

- 24-hour urine free cortisol test

- overnight dexamethasone suppression test

- midnight salivary cortisol test

Confirmatory Test for Hypercorticolism

-low dose dexamethasone suppression test

-midnight plasma cortisol

corticotrophin-releasing hormone (CRH) stimulation test

midnight plasma cortiso confirmatory value?

> 7.5 ug/dl serum cortisol

Reference Method for hypercorticolism for measuring URINE free cortisol

High Performance Liquid Chromatography- Mass Spectrometry (HPLC-MS)

Reference Method for hypercorticolism for Analyzing saliva specimen

LC-MS/MS or immunoassay

Give sign and symptoms for hypercorticolism

-Obesity with thinthin extremities (buffalo hump)

-Hirsutism (nagkakabalbas yung babae)

-Thinning of skin

-poor wound healing

-hypertension

-hypercholesterolemia

- low --WBC count (lymphocytes)

Primary hypocorticolism disorder

Addison's disease

Primary hypocorticolism screening test:

ACTH stimulation test (Same lang rin sa secondary)

Primary hypocorticolism confirmatory test:

Insulin tolerance test (Same lang rin sa secondary)

due to hypothalamic-pituitary insufficiency with loss of ACT

Secondary hypocorticolism

a hypocortisolism disorder that results from the deficiency enzyme

CONGENITAL ADRENAL HYPERPLASIA (CAH)

definitive test for CONGENITAL ADRENAL HYPERPLASIA (CAH)

17-OHP measurement

characterized by:

o pseudohermaphroditism in female infants

o incomplete masculinization in male infants

3 beta-hydroxysteroid dehydrogenaseisomerase deficiency

incomplete masculinization in male infants

3 beta-hydroxysteroid dehydrogenase-isomerase deficiency results to increased ratio of:

o 17 a-hydroxypregnenolone to 17 a- hydroxyprogesterone

o DHEA to androstenedione

3 beta-hydroxysteroid dehydrogenase-isomerase deficiency defective gene

HSD3B2

associated with virilization and hypertension

11 beta-hydroxylase deficiency

increased serum deoxycortisol and urinary 17-OHCS and 17 KS

11 beta-hydroxylase deficiency

11 beta-hydroxylase deficiency defective gene:

CYP11B1

inability to convert 17- hydroxypregnenolone to DHEA and 17- a-hydroxyprogeterone to androstenedione

17-hydroxylase deficiency

17-hydroxylase deficiency indicators:

o amenorrhea

o defective ovarian maturation

o pseudohermaphroditism in males

o hypertension

o hypokalemic alkalosis

17-hydroxylase deficiency defective gene

CYP17

most common form of CAH

21-hydroxylase deficiency

leads to hirsutism in women and other symptoms

21-hydroxylase deficiency

definitive test for 21-hydroxylase deficiency

genotyping cells

21-hydroxylase deficiency common methods for detection

-ACTH stimulation

-17 a-hydroxyprogesterone tests

21-hydroxylase deficiency elevates

elevated plasma levels of pregnanetriol and 17 a-hydroxyprogesterone

increased urinary pregnanetriol and 17 KS

21-hydroxylase deficiency defective gene:

CYP21

most potent mineralocorticoid

aldosterone

Enzyme needed for aldosterone synthesis

18-hydroxysteroid dehydrogenase

Explain Saline Suppression Test process

infusing 2L 0.9% saline over 4 hours

administering 10-12 mg NaCl tablets daily for 3 days

Saline Suppression Test positive result:

>10 ng/dl

PRIMARY HYPERALDOSTERONISM (CONN'S DISEASE symptoms

o hypertension

o hypokalemia

o mild hypernatremia

o metabolic alkalosis

PRIMARY HYPERALDOSTERONISM patient preparation:

patient should be upright for at least 2 hours prior to blood collection

Screening tests for PRIMARY HYPERALDOSTERONISM

Plasma aldosterone concentration (PAC)

Plasma renin activity ratio (PRA)

Ratio =(PAC/PRA)

Ratio (PAC/PRA) = >30 ratio

SUGGESTIVE of primary hyperaldosteronism

Ratio (PAC/PRA) = >50 ratio

DIAGNOSTIC of primary hyperaldosteronism

PRIMARY HYPERALDOSTERONISM confirmatory tests

• Saline suppression test

• Oral sodium loading test

• Fludrocortisone suppression test

• Captopril challenge test

CONN'S DISEASE

PRIMARY HYPERALDOSTERONISM

increased ENaC (Epithelial Sodium Channel)

Liddle's syndrome

resembles primary aldosteronism clinically, but aldosterone and renin are low, with absence of HYPERTENSION

Liddle's syndrome

Bumetanide-sensitive chloride channel mutation

Bartter's syndrome

rare potassium-losing autosomal recessive

Bartter's syndrome

defect in NaCl reabsorption

gitelman's syndrome

Thiazide-sensitive transporter mutation

gitelman's syndrome

destruction of the adrenal glands and deficiency of Mineralococorticoid

Hypoaldosteronism

associated with 21-hydroxylase deficiency

hypoaldosteronism

In HYPOALDOSTERONISM blood samples should be drawn in the ___________________________?

morning before the patient has gotten out of bed

blood sample for renin should be drawn into an ___________________________?

iced EDTA tube

HYPOALDOSTERONISM test give 2

1. Saline Suppression Test

2. Furosemide stimulation test or upright posture

byproducts of cortisol synthesis that are regulated by ACTH

Weak androgens -

Weak androgens circulate bound to

Steroid hormone binding globulin (SHBG)

Give 2 Weak androgens

dehydroepiandrosterone (DHEA) and androstenedione

composed primarily of chromaffin cells that secretes catecholamines

adrenal medulla

chromaffin cells secretes?

catecholamines

precursor of catecholamines

L-tyrosine

Give 2 primary amine

Norepinephrine

Dopamine

Norepinephrine is produced by

sympathetic ganglia

Norepinephrine major metabolites:

3 methoxy-4-hydroxyphenolglycol (MHPG)

vanillylmandelic acid (VMA)

Norepinephrine is found in what specimen

CSF and Urine

fight or flight hormone

Epinephrine

Major metabolite of Epinephrine

vanillylmandelic acid (VMA)