Abstract
Hypoglycin A, an amino acid of novel structure isolated from a tropical fruit, Blighia sapida, is known to cause a profound hypoglycaemia when administered to animals. The in vitro effects of hypoglycin A on the metabolism of glucose C14by normal rat liver slices, rat diaphragm, and rat adipose tissue have been investigated. These experiments have been carried out in the absence and in the presence of insulin. With liver, hypoglycin A decreased the conversion of glucose C14to glycogen and fatty acid but increased the conversion to pyruvate. With diaphragms, hypoglycin A increased conversion of glucose C14to glycogen and carbon dioxide but only in the absence of insulin. No changes in glucose C14metabolism by the epididymal fat pad were demonstrated as a result of the presence of hypoglycin. Theories on the mechanism of action of hypoglycin A are discussed.