RESUMO
Plasma membrane vesicles were prepared from isolated rat liver parenchymal cells. The transport of several amino acids was studied and found to be identical to that in membrane vesicles from whole liver tissue.
Assuntos
Aminoácidos/metabolismo , Fígado/metabolismo , Adenosina Trifosfatases/metabolismo , Animais , Transporte Biológico , Membrana Celular/metabolismo , Cinética , RatosRESUMO
The localization of the sodium-dependent alanine uptake activity in rat liver cells was studied. Fractions representative of the canalicular, the contiguous (lateral) and the blood-sinusoidal surface of the hepatocyte were isolated by means of centrifugal fractionation and density gradient centrifugation. The distribution of various marker-enzyme activities in conjunction with the occurrence of alanine transport activity was studied both in fractions obtained after zonal density gradient centrifugation, and in the subcellular fractions mentioned above. It is concluded that the sodium-dependent alanine transport activity is primarily located in the blood-sinusoidal plasma membrane of the hepatocyte.