A comparison of the effects on blood glucose and ketone-body levels, and of the toxicities, of pent-4-enoic acid and four simple fatty acids

Some effects of the hypoglycaemic compound pent-4-enoic acid in rats and mice, are described. Pent-2-enoic acid, pentanoic acid, cyclopropanecarboxylic acid and cyclobutanecarboxylic acid, which were shown to be non-hypoglycaemic, were used as controls. Pent-4-enoic acid and cyclopropanecarboxylic acid caused ketosis in rats, with a lowering of the blood β-hydroxybutyrate/acetocetate (βHB/AcAc) ratio; some ketosis was caused by the other fatty acids but the βHB/AcAc ratio was not changed. Pent-4-enoic acid caused an increase in free fatty acid concentration in rat plasma. The acute toxicities of these compounds in mice were determined. The mechanism of the hypoglycaemic action of pent-4-enoic acid is discussed in relation to that of hypoglycin.