cardiac markers, lipids and thyroid Functions

Cardiac Troponin I (cTnI)

Apolipoprotein A1

A protein component of high-density lipoprotein (HDL) that plays a crucial role in lipid metabolism and cardiovascular health. it acts as a receptor site for HDL

Atherosclerosis

Increased levels of LDL, VLDL and chylomicrons are associated with

CK (Creatine kinase)

When myocardial infarction occurs, the first enzyme to become elevated is? increases 4 - 6 hours after the symptoms, peaks at 12 - 24 hours and returns to normal within 48 - 72 hours.

Thyroxine (T4)

Is constructed by two diiodotyrosine (DIT) molecules through enzyme thyroperoxidase (TPO). T4 is the primary thyroid hormone assembled within the thyroid gland.

triiodothyronine (T3)

is primarily derived from T4 through the removal of an iodine residue by special enzymes called deiodinases.

T4 to T3 conversion process occurs in the:

• Liver (~60%)

• Intestines (~20%)

• Circulation (~20%)*

T4:T3 ratio is

ratio of 9:1

proteins albumin and thyroxine-binding globulin (TBG)

More than 99% of T4 and T3 in circulation are bound to the

Unbound T3 & T4 is called

Free T3 & Free T4, this is analyte measure in lab

What components are required to assemble thyroid hormones?

Iodine, thyroglobulin, tyrosine, and thyroperoxidase (TPO)

Thyrotropin-Releasing Hormone (TRH) produce by the

hypothalamus which stimulates the release of TSH and the hormone prolactin from the anterior pituitary

thyroid-stimulating hormone (TSH)

produced by the Anterior pituitary gland stimulates the Thyroid gland to produce T3 and T4.

primary hypothyroidism

damage with the thyroid gland. High TSH + Low Free T4

Secondary hypothyroidism

damage in anterior pituitary gland. Low TSH + Low T4

Tertiary Hypothyroidism

Damage in Hypothalamus. High TRH,TSH, T4

Primary hyperthyroidism

damage in thyroid gland. causes

Thyroid nodules, Thyroid adenoma, Graves’ disease, Thyroiditis

low TSH High T4

Secondary hyperthyroidism causes

• Carcinoma

• TSH-secreting tumors

pituitary gland. High TSH, High T4

Tertiary hyperthyroidism

• TRH-secreting tumors

• Very rare

damaged in hypothalamus.

Grave’s Disease

autoimmune disease that produces an autoantibody called thyroid-stimulating immunoglobulin, more common in women >men. High T3&T4

VLDL

Transports endogenous triglyceride.

Endogenous pathway for lipids metabolism

Hepatocytes synthesize trig from carb and fatty acids. trig. are packed in VLDL to be delivered to circulation system.

Exogenous pathway for lipids metabolism

Trig. is transported primarily by Chylomicrons

HDL transports

Cholesterol from the peripheral cells to the liver. HDL is the smallest and most dense consist of 20% lipid, 50 protein

LDL transports

Cholesterol and phospholipid to the peripheral cells.