Octanoic acid inhibits astrocyte volume control: implications for cerebral edema in Reye's syndrome.

Octanoic acid has been implicated in the pathogenesis of cytotoxic cerebral edema in Reye's syndrome. Using astrocytes from primary culture, we studied the dose-dependent effects of octanoate on cellular volume regulation and metabolism. Astrocyte volume recovery following hypoosmotic swelling was stimulated by 1.0 mM octanoate and inhibited by 3.0 mM octanoate. Parallel effects were obtained at these concentrations on the activity of the Na+,K+-dependent ATPase. Cellular ATP concentrations also were reduced 36% with the higher octanoate concentration. These effects of octanoate may contribute to the severe astrocyte swelling observed in the brains of Reye's syndrome patients.