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.
Male: 4.0 – 8.0 pg/ml
Female: 2.0 – 10.0 pg/ml
Luteinizing Hormone-Releasing Hormone is measured by direct radioimmuno-assay.
Patient should not be on any Steroid, ACTH, Gonadotropin, or Estrogen medications, if possible, for at least 48 hours prior to collection of specimen.
3 ml serum or EDTA plasma should be collected and separated as soon as possible. Freeze specimen immediately after separation. Minimum specimen size is 1 ml.
For tumor/tissue and various fluids (i.e. CSF, peritoneal, synovial, etc.) contact the Institute for requirements and special handling.
Ship specimens frozen in dry ice.
J Schopohl, G Mehltretter, R von Zumbusch, T Eversmann, and L von Werder. Comparison of Gonadotropin-Releasing Hormone and Gonadotropin Therapy in Male Patients with Idiopathic Hypogonadism. Fertility and Sterility 56: 1143-1150, 1991.
2. CB Lambalk, J Schoemaker, GP van Rees, J de Koning, and HAMJ van Dieten. Exogenous versus Endogenous Pulses of Luteinizing Hormone-Releasing Hormone and Secretory Patterns of Gonadotropins. Fertility and Sterility 56: 446-452, 1991.