A B C D E F G H I J K L M N O P Q R S T U V W X Y Z #

Thyrotropin Releasing Hormone (TRH)

Test Code
TRH


Alias/See Also
TRH

Quest Code
900791


CPT Codes
83519

Preferred Specimen
2 mL plasma collected in ISI TRH preservative tube, transferred to a plastic screw-cap vial


Minimum Volume
1 mL


Instructions
5 mL EDTA specimen should be collected in the special TRH preservative tube and separated as soon as possible. Freeze specimen immediately after separation. Minimum specimen size is 1 mL. Special preservative tubes are available from InterScience.
Important Precaution: Thyrotropin Releasing Hormone must be collected with the TRH Preservative. No other specimen is acceptable.


Transport Temperature
Frozen


Specimen Stability
Room temperature: unacceptable
Refrigerated: unacceptable
Frozen: 6 months


Methodology
Radioimmunoassay (RIA)

Setup Schedule
Monday-Friday Morning


Report Available
14 days


Clinical Significance
Thyrotropin Releasing Hormone (TRH) is a tripeptide produced primarily by the hypothalamus. TRH is produced from a prohormone, which contains multiple copies of the TRH molecule meaning that several TRH entities can be released from one precursor. It has a stimulatory effect on the pituitary releasing thyrotropin (TSH). TRH secretion is controlled in a negative feedback system by thyroid hormones. Binding of TRH to its receptor causes a rise in calcium which initiates TSH secretion. It also stimulates adenyl cyclase in the pituitary. TRH also stimulates secretion of prolactin, growth hormone in acromegaly, and ACTH in Cushing's and Nelson's syndromes. Levels of TRH are nondetectable or very low in patients with hyperthyroidism and hypothalamic hypothyroidism. Levels are elevated in patients with primary and pituitary hypothyroidism.

Performing Laboratory
Inter Science Institute
Inglewood, CA




The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.