Intensified gradients for endogenous amino acid substrates for transport system L on injecting a specific competitor for that system

Abstract

The injection into the rat of 8.1 mmoles of amino(+/-) -2- aminobicycloheptane-2-carboxylic acid per kg body weight intensified in 2 hr the gradients of several System L substrates characteristically maintained by the liver with respect to the blood plasma. The gradients of amino acids predominantly transported by systems other than L were not, with the exception of proline, significantly influenced. We interpret this effect on System L substrates as supporting the principal service of System L in net cellular exodus of these amino acids, although other factors in the effects are not necessarily excluded.