84250:GONADOTROPIN RELEASING HORMONE (Gn-RH)
Author PeaceHealth Laboratories
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Alias Names: |
Luteinizing Hormone-Releasing hormone (LH-RH) |
Methodology: |
Radioimmunoassay (RIA) |
Edit Date: |
10/14/2009 |
CPT Code: |
83727-90 |
Specimen Collection Details |
Collection: |
One 7.5 mL serum separator tube (SST) or one 5 mL red top tube. Also acceptable: One 4 mL lavender top tube (EDTA). |
Handling: |
Within one hour of collection, centrifuge and separate serum or plasma into a plastic vial. Freeze. Do not allow to thaw. |
Standard Volume: |
3 mL serum or plasma. |
Minimum Volume: |
1 mL serum or plasma. |
Transport: |
Frozen on dry ice. |
Comments: |
Patient should not be on any Steroid, ACTH, Gonadotropin, or Estrogen medications, if possible, for at least 48 hours prior to collection of specimen. |
Rejection Criteria: |
Thawing. |
|
Male |
4.0-8.0 pg/mL |
Female |
2.0-10.0 pg/mL |
Clinical Significance: Gonadotropin-Releasing Hormone (Gn-RH), also known as Luteinizing Hormone-Releasing Hormone (LH-RH), is a decapeptide secreted pulsatily from the hypothalamus. It stimulates the release of the Gonadotropins – Luteinizing Hormone and Follicle Stimulating Hormone – exerting a stronger effect on Luteinizing Hormone. Testosterone and Estradiol, whose release is stimulated by the Gonadotropins, exert a negative feedback control on LH-RH both at the hypothalamic site and by decreasing pituitary receptor binding. LH-RH levels are low in patients with hypothalamic hypogonadism differentiating them from the high levels usually found in primary hypopituitary hypogonadism. Accentuation of the LH-RH pulse occurs at the onset of puberty triggering the release of LH and FSH required in pubertal development. LH-RH is stimulated by Epinephrine and suppressed by Dopamine and opiates. LH-RH and some of its agonists are frequently used to induce ovulation.
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