Effect of octanoate on blood-brain barrier permeability using L-dopa as a marker.

Short-chain fatty acid injection into animals produces coma, seizures, and hyperventilation. One mechanism of coma production may be through alterations in membrane permeability characteristics. The SPG histofluorescence technique was used to evaluate changes in blood-brain barrier permeability to injected L-dopa in rats after intraperitoneal injections of the short-chain fatty acid, sodium octanoate. Diffusion of intravascular fluorescence was observed around brain capillaries in the octanoate-injected rats suggesting an alteration in capillary permeability to L-dopa. Diffusion of fluorescence around neuronal cell bodies and brain fiber tracts was also seen after treatment with octanoate. These findings suggest that octanoate may also alter neuronal membrane function.