Regulation of amino acid transport in isolated rat hepatocytes during development

Journal Article · Thu Jan 01 04:00:00 EST 1987 · J. Cell. Physiol.; (United States)

DOI:https://doi.org/10.1002/jcp.1041300115· OSTI ID:6525564

Leoni, S; Spagnuolo, S; Dini, L; Devirgiliis, L C

The effect of amino acid depletion or supplementation and the effect of glucagon and insulin on the amino acid transport mediated by system A were investigated by determining the uptake of either 2-amino (1-/sup 14/C)isobutyric acid (AIB) or N-methyl 2-amino (1-/sup 14/C)isobutyric acid (MeAIB) in rat hepatocytes, freshly isolated at different stages of pre- and postnatal development. The data obtained show that the Na/sup +/ -dependent uptake was higher at the earliest developmental stages, and steadily decreased until the adult level. The hormones increased AIB and MeAIB uptake enhancing the V/sub max/, while the K/sub m/ was unchanged. This effect was evident in cells from adult and 18-20-day-old fetuses, while no response was present before the 18th day of fetal life and in the prenatal period. Actinomycin D or cycloheximide abolished this hormone-dependent increase. A decrease in AIB and MeAIB transport after incubation in an amino acid-rich medium was demonstrated at all ages tested, but was particularly evident in the prenatal life. The increase in the activity of the system following amino acid starvation was shown to be mostly dependent from de novo protein synthesis in the fetal life; on the contrary in the adult the increase appeared to be more linked to the release from transinhibition of the transport.

• Research Organization: Univ. of Rome La Sapienza, Italy
• OSTI ID: 6525564
• Journal Information: J. Cell. Physiol.; (United States), Journal Name: J. Cell. Physiol.; (United States) Vol. 130:1; ISSN JCLLA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
GLUCAGON
HORMONES
INSULIN
ISOBUTYRIC ACID
LABELLED COMPOUNDS
LIVER CELLS
MAMMALS
MEMBRANE TRANSPORT
METABOLISM
MONOCARBOXYLIC ACIDS
ONTOGENESIS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDE HORMONES
PEPTIDES
POLYPEPTIDES
PROTEINS
RATS
RODENTS
SOMATIC CELLS
VERTEBRATES