Plasma L-arginine levels in a rabbit model of hypercholesterolaemia.

A novel method for the quantitation of L-arginine in plasma samples has been developed, based on the technique of enantiomer labelling coupled to the capillary gas chromatographic separation of amino acids. Using this technique plasma L-arginine levels have been measured in rabbits fed a 1% cholesterol-containing diet and compared with rabbits fed a standard diet. Blood cholesterol levels were significantly elevated in the rabbits fed cholesterol but no significant difference was found in plasma L-arginine levels between the cholesterol-fed and control animals. No D-arginine was found in any of the plasma samples. It is concluded that the impairment in endothelium-dependent relaxation previously described in this animal model of hypercholesterolaemia is not due to deficiency of plasma L-arginine.