The effect of acute feeding of carnitine, acetyl carnitine and propionyl carnitine on basal and A23187-stimulated eicosanoid release from rat carrageenan-elicited peritoneal macrophages.

Little is known about the ability of carnitine to modulate cell functions. As carnitine plays an important role in lipid metabolism we investigated the acute effect of L-carnitine, L-acetyl carnitine and L-propionyl carnitine (300 mg/kg per d; 4 d) on the basal and calcium-ionophore (A23187)-stimulated release of arachidonic acid metabolites from rat carrageenan-elicited peritoneal macrophages. A decrease in the number of peritoneal carrageenan-elicited macrophages was observed after feeding all three compounds. The basal release of prostaglandin E2, 6 keto-prostaglandin F1 alpha and leukotriene B4 was stimulated by all treatments. In contrast, thromboxane B2 production was diminished by feeding carnitine and acetyl carnitine. A23187-stimulated synthesis of 6 keto-prostaglandin F1 alpha and leukotriene B4 was further enhanced by all three compounds. Acetyl carnitine and propionyl carnitine also enhanced thromboxane B2 synthesis. However, no effects on prostaglandin E2 formation were detected. The 6 keto-prostaglandin F1 alpha:thromboxane B2 ratio, calculated from the basal and A23187-stimulated values, was increased by carnitine treatment. In the presence of A23187 there was also an increase in the 6 keto-prostaglandin F1 alpha:leukotriene B4 ratio. We conclude that carnitine, and possibly some of its derivatives, could modify the macrophage component of an inflammation in vivo.