Characteristics of the uridine uptake system in normal and polyoma transformed hamster embryo cells

Technical Report · Mon Jan 01 00:00:00 EST 1973

OSTI ID:7350783

Lemkin, J A

The lability of the uridine uptake system in the normal and polyoma transformed hamster embryo fibroblast was studied. The major areas investigated were: the kinetic parameters of uridine transport, a comparison of changes in cellular ATP content by factors which modulate uridine uptake, and a comparison of the qualitative and quantitative effects of the same modulating agent on uridine transport, cell growth, and cellular ATP content. Uridine uptake into cells in vitro was examined using tritiated uridine as a tracer to measure the amount of uridine incorporated into the acid soluble and acid-insoluble fractions of the cells studied. The ATP content of the cells was determined by the firefly bioluminescence method. It was found that the K/sub t/ for uridine uptake into the normal hamster embryo cell and two polyoma transformed hamster embryo cell lines was identical. However, the V/sub max/ for uridine transport was higher in both polyoma transformed cell lines. Furthermore, the K/sub t/ in both the normal and transformed cell cultured in serum-less or serum-containing media was identical, although the V/sub max/ was higher in the serum-stimulated cell in both the normal and transformed cell. Stimulation of the normal cell with adenosine produced a different K/sub t/ for uridine transport. Preliminary investigations have demonstrated that treatment of the polyoma transformed with adenosine also induces a different K/sub t/ (not shown). The K/sub i/ for phloretin inhibition in serum-less and serum-stimulated normal and polyoma transformed cells was found to be identical in each case.

• Research Organization: Rochester Univ., N.Y. (USA). Dept. of Radiation Biology and Biophysics
• OSTI ID: 7350783
• Report Number(s): UR-3490-869
• Resource Relation: Other Information: Thesis
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ADENOSINE
BIOLOGICAL EFFECTS
ALCOHOLS
ATP
BIOCHEMICAL REACTION KINETICS
BLOOD SERUM
EMBRYONIC CELLS
INSULIN
TUMOR CELLS
URIDINE
UPTAKE
HAMSTERS
ANIMAL CELLS
ANIMALS
AZINES
HETEROCYCLIC COMPOUNDS
HORMONES
HYDROXY COMPOUNDS
KINETICS
MAMMALS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PEPTIDE HORMONES
PYRIMIDINES
REACTION KINETICS
RIBOSIDES
RODENTS
URACILS
VERTEBRATES
550200* - Biochemistry