Page 15 - Module 1-Anatomy and Physiology of Growth Hormone Function Final (Interactive)

Module 1: Anatomy and Physiology of Growth Hormone

• Administration of amino acids, particularly arginine, also increases GH release by
decreasing somatostatin release. In contrast, increased glucose and
nonesterified fatty acid levels decrease GH release.

Growth Hormone

As mentioned, one of the key hormones involved in the growth of the human body,
protein synthesis, metabolism, and cellular replication is growth hormone, also called
somatotropin—a protein hormone produced and secreted by the anterior pituitary
gland. Its primary function is anabolic; it promotes protein synthesis and tissue
building. Growth-Hormone-Releasing Hormone (GHRH) and Growth-Hormone-
Inhibiting Hormone (GHIH), (aka somatostatin), are the two hypothalamic hormones
that control the release of GH from the anterior pituitary gland.
Direct metabolic functions

Two of growth hormone’s key metabolic functions include lipolysis and
glycogenolysis.

Lipolysis: GH stimulates the breakdown of adipose tissue, which
releases fatty acids into the blood. When this occurs, some tissues
are able to switch from glucose as their primary energy source to fatty
acids. This also means that less glucose is taken up from the
bloodstream by these same tissues.

Glycogenolysis: GH stimulates the liver to break down glycogen to
glucose when additional glucose is needed. Blood glucose levels rise
as a result.

The effects of GH on adipose tissue will be covered in more detail later in this
module.

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