Gigantism is a serious condition that is nearly always caused by an adenoma,which is a tumor of the pituitary gland.

The pituitary tumor cells secrete too much GH, leading to many changes in the body.

Physiology:

Gigantism usually occurs in childhood or young adulthood. If the a pituitary tumor that secretes GH develops after the bone growth fuses the result.

Normal GH physiology:

GH is secreted by the pituitary gland in pulsation fashion, meaning that it's level goes up and down significantly throughout the day.

For this reason, GH measured at a random time of the day may be meaningless for diagnosis. GH has direct affects on the body, but like most pituitary hormones acts on other specialized gland cells in the body to stimulate the release of another hormone.

GH acts on special cells in the liver, leading to the release into the blood

stream a hormone called insulin-like Growth Factor. ( IGF-1)

Both IGF-1 and GH are important for bone and muscle growth and maintenance.

Normal Control of GH Production

A part of the brain called the hypothalamus controls the amount of GH production

by sending chemicals down the pituitary gland. These chemicals are called

neuropeptides.

The main chemical that stimulates GH release is called growth hormone

releasing hormone. ( GHRH)-

What is Gigantism?