hGH Terminology Glossary
Research of the body's hormone-secreting glands, also known as Endocrinology, is a complex Science. Some of the terminology used in the study of growth, including hormone therapy and disorders, may be unfamiliar to you. You may find this glossary helpful to acquaint you with those terms and some basic concepts of this Science.
Abbreviations
- AGHD:
- See adult growth hormone deficiency.
- GABA:
- See Gamma-aminobutyric acid.
- GH:
- Growth hormone. See human growth hormone.
- GHR:
- Growth hormone releaser.
- hGH:
- Human growth hormone. A hormone secreted by the pituitary gland that, in children, causes physical growth. In adults as well as children, hGH is essential to maintain healthy body composition and metabolism (in other words, to improve one's ratio of fat to lean body mass). Also known simply as growth hormone or somatotropin.
- IGF-I:
- Insulin-like Growth Factor I (somatomedin). A chemical produced by the liver and other tissues in response to human growth hormone (hGH). It plays a role in helping hGH cause changes in cells that lead to growth.
- PGHD:
- See pediatric growth hormone deficiency.
Ingredient Glossary
Important ingredients that are commonly found in hGH releasing products. Other additives have beneficial effects. See ingredient label of individual products to see which apply.
- Gamma-aminobutyric acid (GABA):
- GABA, an amino acid, acts as an inhibitory neurotransmitter found in the nervous system and helps induce relaxation and deeper sleep cycles. It is a synthesized compound that naturally stimulates the activation of muscle synapses between nerves and muscle cells, which can promote leaner muscle tissue and lower fat levels. GABA also stimulates certain glands, such as the anterior pituitary gland, leading to higher levels of Human Growth Hormone (hGH).
- Ginseng:
- Ginseng has been used for centuries for its medicinal effects. Ginseng increases resistance to stress, improves circulation, and mental functioning. In general, it improves the quality of life for the users, and has also been used as an aphrodisiac.
- L-Arginine:
- L-Arginine supplementation has many benefits and plays an important role in cell division, the healing of wounds, removing ammonia from the body, immune function, and the release of hormones. It is one of the chemical triggers that stimulate anabolic muscle growth and, thusly, remove fat.
- L-Glutamine:
- Glutamine, like other amino acids, is biochemically important as a constituent of proteins. It is also crucial in nitrogen metabolism. Glutamine prevents deterioration of the stomach and intestinal linings. It may also help to prevent ulcers. Glutamine is one of the most prevalent amino acids in the human body, but in times of stress or increased energy output, body tissue will need more glutamine than usual. More notably though, research reveals that glutamine taken orally in combination with Glycine and niacin can enhance GH secretion in healthy middle-aged and elderly subjects.
- L-Glycine:
- Glycine is an amino acid found in protein and increases neurotransmission activity of hormones involved in memory and cognition, which helps alleviate the symptoms of spasticity. Studies have found that Glycine helps increase hGH levels. One study showed that 30 grams of Glycine raised serum hGH levels 10 times in patients following gastric surgery. Very early findings may also suggest it has antioxidant and anti-inflammatory effects. These studies are still ongoing.
- L-Lysine:
- Lysine is an essential amino acid for all protein in the body and plays a major role in calcium absorption, building muscle protein, recovering from surgery or sports injuries and the body's production of hormones, enzymes, and antibodies. Evidence suggests that lysine in combination with arginine may increase thymic hormone secretions, thus building up the body's immune system.
- L-Tyrosine:
- Tyrosine is an essential amino acid and a precursor of the neurotransmitters dopamine, norepinephrine, epinephrine (adrenaline) and thyroid hormones. It is used to enhance alertness and mood. L-Tyrosine is sometimes recommended by practitioners as an aid for weight loss or clinical depression. Increased secretion of melanin in the skin from tyrosine has been noted as well.
- L-Valine:
- Valine is another essential amino acid. On the cellular level, valine is burned for fuel to support muscle recovery after physical exertion and aids in growth of new tissue. Valine is not readily available in the human body. While it has no profound effects on its own, it is used symbiotically with other aminos; much like a buffering solution. It is this synergetic relationship with such aminos as L-Arginine and L-Isoleucine that helps promote lean muscle growth.
Definitions
- adolescence:
- The teenage years; the physical and mental transition from child to adult (see puberty).
- adrenal glands:
- Located above the kidneys in the lower back, these two glands produce several kinds of hormones.
- adult growth hormone deficiency (AGHD):
- Growth hormone deficiency during adulthood. Adults need growth hormone to maintain healthy body composition and metabolism. AGHD occurs when the pituitary gland either is missing or does not secrete enough growth hormone. It may be the continuation of a growth hormone deficiency that began in infancy or childhood (childhood-onset AGHD), or it may begin in adulthood (adult-onset AGHD).
- adult-onset AGHD:
- Adult growth hormone deficiency that begins in adulthood.
- amino acids:
- Amino acids are the basic structural building blocks of proteins that determine their shape and function. There are twenty standard amino acids that are needed for the body to make the proteins for enzymes, hormones, muscle, bone, skin, organs, etc. A number of these amino acids have been shown to induce hGH secretion.
In addition to protein synthesis, amino acids have other biologically-important roles. Glycine and glutamine are neurotransmitters as well as standard amino acids in proteins. Many amino acids are used to synthesize other molecules, for example, L-Arginine is used to synthesize the hormone nitric oxide. Numerous non-standard amino acids are also biologically-important, such as Gamma-aminobutyric acid (GABA), which is another neurotransmitter.
Of the twenty standard amino acids, humans can only produce half of them. The other ten must be supplied in the food we eat or supplemented; they are considered to be essential. If we fail to obtain one of the essential amino acids, then degradation of the body's proteins goes into acquiring it. Unlike fats and starches, the human body will not store excess amino acids and we must get them every day.
Essential amino acids include Arginine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Tyrosine, Trytophan and Valine. All other amino acids are considered to be non-essential. - androgen:
- A type of natural or artificial steroid that acts as a male sex hormone.
- bone age:
- The stage of development or maturity of the bones. In most children, bone age will be about the same as chronological (actual) age, but in some children it may be advanced (ahead) or delayed (behind). It is measured by taking an X-ray, usually of the hand and wrist, to look at the bones and compare them with standards for boys and girls of various ages.
- childhood-onset AGHD:
- Adult growth hormone deficiency that begins in infancy or childhood.
- deficiency:
- A lack of something; in the case of endocrine deficiency, not enough of a hormone.
- endocrine system:
- The system of glands in the human body that are responsible for producing hormones.
- endocrinology:
- The branch of medicine dealing with the endocrine system and its hormones.
- estrogen:
- A female sex hormone, also present in small quantities in males. Estrogen stimulates secondary sexual characteristics in women (for example, the development of breasts) and also helps bones to grow.
- gland:
- An organ or a specialized group of cells in the body that produces secretions, such as insulin or bile, or excretions, such as sweat.
- hormones:
- Chemicals secreted into the bloodstream in small amounts by glands located throughout the body. Hormones "set in motion" many life processes; growth, puberty, reproduction, and metabolism.
- hypogonadism:
- A condition in which sex organs such as the testes or ovaries are under active.
- hypothyroidism:
- A condition in which the thyroid gland is under active.
- idiopathic:
- Occurring without a known cause.
- malnutrition (malnourishment):
- Poor nourishment resulting from insufficient food, improper diet, etc.
- metabolism:
- The chemical and physical processes continuously occurring in the body and its cells, such as when foods are turned into energy, tissue, or waste products.
- orthomolecular medicine:
- The orthomolecular field is based on research in biochemistry, nutrition, medicine, and pharmaceuticals combined with the clinical experience of a number of physicians and physician scientists. Many mainstream nutritional studies, both recent and historical, provide investigational and clinical support for their theories. It is believed that orthomolecular therapies are intrinsically less likely to cause dangerous side-effects or harm, since they utilize only molecules which are normally present in the body through healthy diet or normal metabolism.
- ovaries:
- The female sex organs that produce eggs and secrete the female sex hormone estrogen.
- pediatric growth hormone deficiency (PGHD):
- Growth hormone deficiency during infancy or childhood. PGHD occurs when the production of growth hormone by the pituitary gland is disrupted. This results in abnormalities of many body processes, including growth and development, production of muscle protein, and breakdown of fats. Although PGHD is uncommon, it may occur at any time during infancy or childhood, and there are many possible causes.
- pituitary gland:
- A small gland attached by a stalk to the base of the brain; it secretes hormones that control other glands and regulate growth. It is sometimes called the "master gland."
- proteins:
- Compounds that are found throughout the body and serve many important functions. They are the main components of cells. Growth hormone and IGF-I are examples of proteins.
- puberty:
- The time of life when the greatest amount of growth occurs and the development of sexual characteristics (such as pubic hair, breasts in females, and lower voice in males) takes place.
- somatotropin:
- Another name for human growth hormone.
- syndrome:
- A set of features or symptoms often occurring together and believed to stem from the same cause.
- synthesize:
- To create something, such as chemicals in the body, from simpler, raw materials.
- testes:
- The male sex organs that secrete the male sex hormone testosterone.
- testosterone:
- A male sex hormone, also present in small quantities in females. Testosterone stimulates secondary sexual characteristics in men (for example, deepening of the voice), accelerates growth, and affects metabolism.
- thyroid gland:
- A large gland situated in front and on either side of the trachea (windpipe) that secretes the hormone thyroxine, which helps regulate body growth and metabolism.
