Tuesday, July 28, 2009

What is achlorhydria?

A condition resulting from the lack of STOMACH ACID. DIARRHEA, stomach discomfort, and bloating are common symptoms of achlorhydria, which has serious effects. It can lead to MALNUTRITION, even when the diet is well balanced, because achlorhydria drastically reduces the efficiency of DIGESTION. A chronic MALABSORPTION syndrome leads to deficiencies of VITAMIN B12, CALCIUM, IRON, and other nutrients and sets the stage for chronic FATIGUE, OSTEOPOROSIS, ANEMIA, and serious infections. Although causes of achlorhydria are unknown, lowered stomach acid production is associated with anemia, stomach inflammation, CELIAC DISEASE, diabetes, lupus, myasthenia gravis, rheumatoid ARTHRITIS, and some forms of cancer. Limited stomach acid production, not the absence of stomach acid, is termed HYPOCHLORHYDRIA. It is not as severe a condition as achlorhydria, although unless corrected, the ensuing malabsorption syndrome can have similar, detrimental longrange effects on health. In either situation patients may be advised to take supplemental hydrochloric acid in the form of BETAINE HYDROCHLORIDE or glutamic acid hydrochloride with meals to enhance digestion. These supplements should be used with medical supervision because of the danger of overdosing.

What is acetoacetic acid (acetoacetate)

The most prevalent of the KETONE BODIES, which are acids produced by the liver. Acetoacetic acid is a useful fuel; it is readily oxidized by the heart and brain for the production of ATP, the energy currency of cells.
Though small amounts of ketone bodies are normally produced by liver metabolism, an excessive buildup of acetoacetic acid and its derivative, BETA HYDROXYBUTYRIC ACID, in the blood (ketonemia) can occur during excessive fat breakdown, when the liver cannot completely oxidize massive amounts of fatty acids released from fat (ADIPOSE TISSUE). Conditions conducive to excessive acetoacetic acid production include STARVATION (prolonged FASTING), crash DIETING, uncontrolled DIABETES MELLITUS, and chronic ALCOHOLISM.
Ketone body production serves an important role in the physiologic adaptation to starvation. With prolonged starvation, the blood levels of ketone bodies rise, and more of them cross the BLOOD-BRAIN BARRIER to be taken up by nerve tissue, where they are burned for energy. Consequently, the brain requires less blood glucose (blood sugar) for energy at a time when this fuel is at a premium. The sustained build-up of acetoacetic acid in the blood (KETOSIS) can acidify the blood, leading to metabolic ACIDOSIS, and alter the acid-base balance of the body, a potentially dangerous condition.

What is acetic acid?

During fermentation, certain bacteria produce acetic acid by oxidizing alcohol when exposed to air. VINEGAR contains 4 percent to 6 percent acetic acid, which gives vinegar its characteristic sour taste. As vinegar, acetic acid is a common ingredient in food preparation.
One of the simplest organic acids, acetic acid contains only two carbon atoms. It is classified as a weak acid because it is only partially ionized, unlike strong mineral acids, such as hydrochloric acid.
Acetic acid plays a pivotal role in metabolism. To be metabolized, acetic acid must be activated as acetyl CoA, in which acetic acid is bound to a carrier molecule, COENZYME A, which is in turn derived from the B vitamin PANTOTHENIC ACID. Metabolic pathways that oxidize fatty acids, carbohydrate, and amino acids for energy, all yield acetyl CoA, the common intermediate by which carbons from these fuels enter the KREB’S CYCLE to be oxidized to carbon dioxide. Alternatively, acetyl CoA can be used as a building block. It forms saturated fatty acids, cholesterol, and ketone bodies. Nerve cells can use it to form the NEUROTRANSMITTER, ACETYLCHOLINE. Tissues combine acetic acid with amino sugars to form a family of sugar derivatives like Nacetylglucosamine and N-acetylgalactosamine that help define recognition sites on the surface of cells and blood group specificities, such as the A, B, O, and Lewis blood groups used in blood typing.