Search results
Results from the WOW.Com Content Network
The accumulation of acetyl-CoA in turn produces excess ketone bodies through ketogenesis. [11] The result is a rate of ketone production higher than the rate of ketone disposal, and a decrease in blood pH. [12] In extreme cases the resulting acetone can be detected in the patient's breath as a faint, sweet odor.
Ketone bodies are water-soluble molecules or compounds that contain the ketone groups produced from fatty acids by the liver (ketogenesis). [1] [2] Ketone bodies are readily transported into tissues outside the liver, where they are converted into acetyl-CoA (acetyl-Coenzyme A) – which then enters the citric acid cycle (Krebs cycle) and is oxidized for energy.
In physiological ketosis, ketones in the blood are elevated above baseline levels, but the body's acid–base homeostasis is maintained. This contrasts with ketoacidosis, an uncontrolled production of ketones that occurs in pathologic states and causes a metabolic acidosis, which is a medical emergency.
Ketoacidosis is caused by the uncontrolled production of ketone bodies. Usually the production of ketones is carefully controlled by several hormones, most importantly insulin. If the mechanisms that control ketone production fail, ketone levels may become dramatically elevated and cause dangerous changes in physiology such as a metabolic acidosis.
Ketones contain a carbonyl group −C(=O)− (a carbon-oxygen double bond C=O). The simplest ketone is acetone (where R and R' are methyl), with the formula (CH 3) 2 CO. Many ketones are of great importance in biology and industry. Examples include many sugars , many steroids (e.g., testosterone), and the solvent acetone. [1]
During ketosis, however, acetyl-CoA from fatty acids yields ketone bodies, including acetone, and up to ~60% of acetone may be oxidized in the liver to the pyruvate precursors acetol and methylglyoxal. [19] [4] Thus ketone bodies derived from fatty acids could account for up to 11% [citation needed] of gluconeogenesis during starvation.
People with type 2 diabetes who were given ketones before exercise had increased cardiac output, stroke volume, and peripheral muscle oxygenation, which are all indicators of improved heart function.
β-hydroxybutyrate (the conjugate base of β-hydroxybutyric acid, drawn above) despite chemically containing a carboxylate group instead of a ketone, is the principal "ketone body" in diabetic ketoacidosis. DKA is common in type 1 diabetes as this form of diabetes is associated with an absolute lack of insulin production by the islets of ...