enzyme multiplied immunoassay – homogenous. Sample analyte competes with enzyme labeled antigen for binding site on antibody.If there’s a lot of analytes, there’ll be less labeled binding which means that they’ll be free to respond to analytes for spectrophotometer reading. NADH production. 1) substrate (glucose6PO4), coenzyme (NAD+) and antibody. 2) enzyme labeled drugg and buffer
Serum (FPIA/photometric called trinder) Trinder: react it with Fe3+ to form color complex at 540 nm.
Primary testicular failure
Increased LH, FSH due to decreased testerone (hypergonadotropic).
distinguish between cushing’s syndrome and disease. Adrenal tumor = no ACTH. Ectopic = lots of ACTH.
Dexamethasone suppression test
1 mg dex at night. Collect at 8 am. Normal results is when its low <3. Cushing's is elevated. Cortisol is usually not supressed in non pituitary tumors.It is a basically does a negative feedback on the hypothalamus than cortisol, but with cushing's it doesn't work.
plasma cortisol and ACTH levels and stimulation helps diagnose primary adrenal insufficiency.
with plasma cortisol and ACTH level, helps diagnose if its secondary or tertiary adrenal insufficiency.
24 hour urine free cortisol – if elevated that means its ( over 120) cushing’s syndrome.
Diurenal variation – check plasma at 8 am (high) and 4 pm (low).
produced by anterior pituitary in response to low free T4 or T3. A normal TSH rules out thyroid disease. TSH is low in primary hyperthyroidism and high in primary hypothryodism.