Short-chain polyhydroxymonocarboxylic acids as physiological signals for food intake

In order to clarify the effects of endogenous organic acids on short and long-term feeding behavior, ingestive behavior was monitored for 2 hr before and after intra-third ventricular infusions of 3,4-dihydroxybutyric acid (2-deoxytetronic acid, 2-DTA), 2,4,5-trihydroxypentanoic acid (3-deoxypentonic acid, 3-DPA), and 3-hydroxybutyric acid (3-HBA). In addition, meal patterns were recorded for 2 days before and after the ventricular infusions. 2-DTA suppressed both short and long-term feeding by decreasing meal size (MS). 3-DPA elicited transient feeding behavior, but caused no change in long-term feeding. 3-HBA initially stimulated feeding, but subsequently suppressed long-term feeding by decreasing MS and prolonging postprandial intermeal interval (IMI). The suppressive effects of 3-HBA on feeding behavior lasted about 24 hr longer than those of 2-DTA. Based upon these observations as well as our previous reports, it appears that some of the processes affecting hunger and satiation are mediated by changes in central and peripheral concentrations of these organic acids.