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Functional hepatocyte heterogeneity in glutamate, aspartate and α-ketoglutarate uptake: A histoautoradiographical study

1991; Lippincott Williams & Wilkins; Volume: 13; Issue: 2 Linguagem: Inglês

10.1002/hep.1840130208

1527-3350

Barbara J. Stoll, Sabine McNelly, Hans-Peter Buscher, Dieter Häussinger,

Diet and metabolism studies

[ 3 H]glutamate, [ 3 H]α-ketoglutarate or [ 3 H]aspartate was injected in physiological concentrations into antegrade (from portal to hepatic vein) or retrograde (from hepatic to portal vein) perfused rat liver, and the tissue distribution of radioactivity was studied by histoautoradiography. Independent of the direction of perfusion, radioactivity was accumulated in a small perivenous liver parenchymal cell population, which surrounded the terminal hepatic venules as a layer of about two to five cells thick. In contrast, accumulation of radioactivity in periportal hepatocytes was low and sometimes not detectable. This distribution pattern roughly resembled that described for the immunohistochemical distribution of glutamine synthetase in liver. The present histoautoradiographic findings demonstrate a predominant uptake of vascular glutamate, aspartate and ketoglutarate into a small perivenous cell population. They confirm previous label incorporation studies in the metabolically intact liver, demonstrating an almost exclusive uptake of vascular glutamate and α-ketoglutarate into perivenous glutamine synthetase containing hepatocytes. In addition, evidence is presented suggesting that perivenous uptake of α-ketoglutarate may be one determinant for hepatic glutamine synthesis, at least under the experimental conditions used here. (Hepatology 1991;13:247-253).