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Definition

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 Names

Luteinizing hormone response to gonadotropin-releasing hormone

How the test is performed

A 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 test

No special preparation is necessary.

How the test will feel

When 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 performed

This 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.

  • Primary hypogonadism starts in the testicle or ovary.
  • Secondary hypogonadism starts in the hypothalamus or pituitary gland.

This test may be also be done to evaluate low testosterone levels in men or low estradiollevels in women.

Normal Values

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

An 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:

What the risks are

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:

  • Excessive bleeding
  • Fainting or feeling lightheaded
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)
Special considerations

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.

References

Webster 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.

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What does GnRH stand for?

GnRH stands for Gonadotropin-Releasing Hormone. It is a hormone produced in the hypothalamus that stimulates the release of other hormones involved in reproduction, such as LH and FSH.


What is gnrh hormone?

GnRH (Gonadotropin-releasing hormone) is a hormone produced by the hypothalamus in the brain. It regulates the production and release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland, which in turn control the release of sex hormones from the ovaries and testes. GnRH plays a crucial role in the regulation of reproductive functions in both males and females.


What stimulates luteinizing hormone?

Luteinizing hormone (LH) is primarily stimulated by the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. GnRH prompts the anterior pituitary gland to secrete LH, which plays a crucial role in regulating the menstrual cycle and ovulation in females, as well as testosterone production in males. Additionally, estrogen levels can provide positive feedback to enhance LH secretion during the menstrual cycle.


What do the GnRH directly stimulate the release of?

GnRH (Gonadotropin-Releasing Hormone) directly stimulates the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary gland. These hormones play a crucial role in regulating the reproductive system, including the production of sex hormones such as estrogen and testosterone.


What causes the hypothalamus to release GRH?

The hypothalamus releases gonadotropin-releasing hormone (GnRH) in response to various factors such as stress, low sex steroid levels, and certain neurotransmitters. GnRH acts on the pituitary gland to stimulate the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn regulate the production of sex hormones.

Related Questions

How are the FSH and LH are released by the hypothalamus?

FSH and LH are released by the hypothalamus in response to gonadotropin-releasing hormone (GnRH) stimulation. GnRH is released in pulses into the bloodstream, which then triggers the release of FSH and LH from the pituitary gland. These hormones play a key role in regulating the reproductive system and stimulating the production of sex hormones in both males and females.


GnRH directly stimulates the release of?

FSH and LH


What stimulates LH release by the anterior pituitary?

Luteinizing hormone (LH) release by the anterior pituitary is primarily stimulated by the gonadotropin-releasing hormone (GnRH) produced by the hypothalamus. GnRH is released in a pulsatile manner, which triggers the anterior pituitary to secrete LH, along with follicle-stimulating hormone (FSH). Additionally, the levels of sex steroids, such as estrogen and testosterone, can modulate the release of LH, particularly in feedback mechanisms during the menstrual cycle or in response to reproductive cues.


What does GnRH stand for?

GnRH stands for Gonadotropin-Releasing Hormone. It is a hormone produced in the hypothalamus that stimulates the release of other hormones involved in reproduction, such as LH and FSH.


What gland is LH found in?

LH or Luteinizing Hormone is released from the anterior pituitary gland which is stimulated by GnRH or Gonadotropin-releasing hormone in the hypothalamus.


What allows Follicle-stimulating hormone and Luteinizing hormone levels to increase again?

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.


How is lh regulated?

Luteinizing hormone (LH) regulation primarily occurs through the hypothalamic-pituitary-gonadal (HPG) axis. Gonadotropin-releasing hormone (GnRH) released from the hypothalamus stimulates the pituitary gland to secrete LH. The levels of LH are further regulated by feedback from sex hormones such as estrogen and testosterone, which inhibit or stimulate GnRH and LH production depending on the physiological context, such as during the menstrual cycle or spermatogenesis. Additionally, factors like stress, nutrition, and overall health can also influence LH levels.


Where is Gnrh produced?

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.


What is the function of GnRH?

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 is gnrh hormone?

GnRH (Gonadotropin-releasing hormone) is a hormone produced by the hypothalamus in the brain. It regulates the production and release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the pituitary gland, which in turn control the release of sex hormones from the ovaries and testes. GnRH plays a crucial role in the regulation of reproductive functions in both males and females.


What are the important horomones invovled in the control of reproduction?

GnRH, LH, FSH, inhibin, testosterone (in males), estrogens and progesterone (in females).


What stimulates luteinizing hormone?

Luteinizing hormone (LH) is primarily stimulated by the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. GnRH prompts the anterior pituitary gland to secrete LH, which plays a crucial role in regulating the menstrual cycle and ovulation in females, as well as testosterone production in males. Additionally, estrogen levels can provide positive feedback to enhance LH secretion during the menstrual cycle.