LH response to GnRH is a blood test to indirectly determine the pituitary gland's ability to appropriately respond to gonadotropin releasing hormone (GnRH), a hormone produced in the hypothalamus.
Alternative NamesLuteinizing hormone response to gonadotropin-releasing hormone
How the test is performedA blood sample is drawn prior to an injection of GnRH. After a specified time, other blood samples are drawn so that LH can be measured.
Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.
Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
How to prepare for the testNo special preparation is necessary.
How the test will feelWhen the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performedThis test is used to tell the difference between primary and secondary hypogonadism , a condition in which the sex glands produce little or no hormones. In men, the sex glands (gonads) are the testes. In women, the sex glands are the ovaries.
This test may be also be done to evaluate low testosterone levels in men or low estradiollevels in women.
Normal ValuesNormal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
What abnormal results meanAn excessive LH response suggests that gonadal failure is due to a problem within the ovaries or testes.
A reduced LH response suggests a problem with the hypothalamus or pituitary gland.
Abnormal results may also be due to:
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks related to having blood drawn are rare but may include:
In women, estrogen levels rise during the menstrual cycle until there is enough estrogen present to stimulate the release of GnRH and lutenizing hormone (LH).
Progesterone in high concentrations (for example, during the luteal phase of the menstrual cycle or during pregnancy) reduces the response of the pituitary gland to GnRH.
ReferencesWebster RA. Reproductive function and pregnancy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: Saunders Elsevier; 2006:chap 25.
Ferri FF. Laboratory tests and interpretation of results. In: Ferri FF, ed. Ferri's Clinical Advisor 2009. 1st ed. Philadelphia, Pa: Mosby Elsevier; 2009:section IV.
LH response to GnRH is a blood test to help determine if your pituitary gland can correctly respond to gonadotropin releasing hormone (GnRH). GnRH is a hormone produced in the hypothalamus.
Alternative NamesLuteinizing hormone response to gonadotropin-releasing hormone
How the test is performedA blood sample is taken, and then you are given an shot of GnRH. After a specified time, other blood samples are taken so that LH can be measured.
For information on how the blood sample is taken, see: Venipuncture
How to prepare for the testNo special preparation is necessary.
How the test will feelWhen the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performedThis test is used to tell the difference between primary and secondary hypogonadism , a condition in which the sex glands produce little or no hormones. In men, the sex glands (gonads) are the testes. In women, the sex glands are the ovaries.
This test may be also be done to evaluate low testosterone levels in men or low estradiollevels in women.
Normal ValuesNormal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.
What abnormal results meanAn excessive LH response suggests a problem within the ovaries or testes.
A reduced LH response suggests a problem with the hypothalamus or pituitary gland.
Abnormal results may also be due to:
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks related to having blood drawn are rare but may include:
In women, estrogen levels rise during the menstrual cycle until there is enough estrogen present to stimulate the release of GnRH and lutenizing hormone (LH).
Progesterone in high concentrations (for example, during the luteal phase of the menstrual cycle or during pregnancy) reduces the response of the pituitary gland to GnRH.
ReferencesWebster RA. Reproductive function and pregnancy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: Saunders Elsevier; 2006:chap 25.
Ferri FF. Laboratory tests and interpretation of results. In: Ferri FF, ed. Ferri's Clinical Advisor 2012. 1st ed. Philadelphia, Pa: Mosby Elsevier; 2011:section IV.
Reviewed ByReview Date: 09/12/2011
Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Redmond, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
FSH and LH
It is produced by Hypothalamus.It stimulates production FSH and LH.
GnRH-gonadotropin realeasing hormone
inhibits the production of FSH and LH.
Follicle-Stimulating Hormone (FSH)The anterior pituitary gland is controlled via portal system of veins from the Hypothalamus. Directly the Hypothalamus secretes GnRH (gonadtropin releasing hormone) to the anterior pituitary gland to stimulate the release of the gonadtropins FSH (follicle stimulating hormone) and LH (lutenizing hormone). Testosterone is a male sex hormone that is synthesized by cells stimulated by LH & FSH
FSH and LH
FSH and LH
It is produced by Hypothalamus.It stimulates production FSH and LH.
LH or Luteinizing Hormone is released from the anterior pituitary gland which is stimulated by GnRH or Gonadotropin-releasing hormone in the hypothalamus.
Once GnRH levels increase, FSH and LH levels will increase. During pregnancy, GnRH is not required which is responsible for the lack or absence of FSH and LH production. Prolactin can also decrease GnRH production which again will decrease FSH and LH. Luteinizing hormone (LH) levels can also be affected by another hormone called melatonin, which is regulated by the hypothalamus and released by the pineal gland in repsonse to the amount of broad-spectrum light that enters the eyes.
GnRH, short for gonadotropin-releasing hormone, is released by the part of the brain known as the hypothalamus. At the beginning of the menstual cycle, the hypothalamus releases GnRH. The GnRH then stimulates a different part of the brain, the pituitary gland, to produce two hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
what i learned in class was that GnRH was produced by the Hypothalamus gland, and it stimulated the release of FSH and LH in the Anterior lobe of the pituitary gland.
GnRH, LH, FSH, inhibin, testosterone (in males), estrogens and progesterone (in females).
The hypophysial portal system carries gonadotropin-releasing hormone (GnRH) from the hypothalamus to the anterior pituitary. It stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary.
EstrogenProgesteroneFollicle-stimulating hormone (FSH)Luteinizing hormone (LH)Gonadotropin-releasing hormone (GnRH)
In both male and female,GnRH produced and released by Hypothalamus.It stimulates Anterior Pitutory to release FSH and LH
GnRH-gonadotropin realeasing hormone