Amino acid uptake regulation by cell growth in cultured hepatocytes isolated from fetal and adult rats.
Amino acid uptake mediated by system A was studied in cultured fetal and adult hepatocytes, subjected to growth stimulation by EGF and insulin, or to growth inhibition by high cell density. The mitogenic stimulation induced a strong transport increase only in fetal cells, while the cell density-dependent growth inhibition, probably mediated by molecules present on adult hepatocyte membranes, provoked the decrease of amino acid uptake only in the adult cells. The results indicate that the different modulation of amino acid transport by cell growth is dependent on the age and the differentiation stage of hepatocytes.
Leoni
S
S
Dept. of Cellular and Developmental Biology, University La Sapienza, Rome, Italy.
Spagnuolo
S
S
Massimi
M
M
Terenzi
F
F
Conti Devirgiliis
L
L
D000367:Age Factors; D000596:Amino Acids / Q000378:metabolism*; D000621:Aminoisobutyric Acids / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005865:Gestational Age; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D000596:Amino Acids; D000621:Aminoisobutyric Acids; C100049:2-aminoisobutyric acid; D004815:Epidermal Growth Factor; D004247:DNA