High-performance liquid chromatographic analysis of biogenic amines in cells and in culture media using on-line dialysis and trace enrichment.

A highly sensitive method is presented for the automatic quantitative detection of DOPA metabolites in low concentrations in cells derived from the neural crest using reversed-phase HPLC in combination with fluorescence and electrochemical detection. The HPLC system was combined with on-line dialysis and on-line trace enrichment for the detection of small quantities of DOPA metabolites in culture media. Parameters like detector settings, pH, dialysis time and flow-rates are evaluated and optimized.

In-situ cytidine-deaminase activity and chromosome 1P deletion in human neuroblastoma cells.

Cytidine deaminase can cause the deamination of cytotoxic analogues of cytidine or rescue cells from the cytotoxicity of uracil analogues. Therefore, cytidine deaminase influences the cytotoxicity exerted by these compounds. We investigated the activity of this enzyme in situ in neuroblastoma cell-line cells.

Quantitative analysis of the pyrimidine metabolism in pheochromocytoma PC-12 cells.

A detailed quantitative study of pyrimidine metabolism in exponentially growing rat pheochromocytoma PC-12 cells has been performed. The sizes of ribonucleotide pools have been analysed and the pathways and the rates of metabolism of uridine, cytidine and aspartic acid have been determined, based on the incorporation of radioactive label. The fluxes of radioactive label through uridine-cytidine kinase, cytidine deaminase.

The effect of cyclopentenyl cytosine on human SK-N-BE(2)-C neuroblastoma cells.

Human neuroblastoma SK-N-BE(2)-C cell-line cells were cultured in the presence of various concentrations of cyclopentenyl cytosine (CPEC). In the absence of cytidine, the IC50 value of CPEC for SK-N-BE(2)-C cells was 100 nM after 72 hr drug exposure. The IC20 value was 1 microM after 24 hr of exposure to CPEC in the presence of 10 microM cytidine, whereas in the absence of cytidine, CPEC at 1 microM resulted in an IC40 value after 24 hr.

Cyclopentenyl cytosine and neuroblastoma SK-N-BE(2)-C cell line cells.

We studied the effect of cyclopentenyl cytosine (CPEC) on human neuroblastoma SK-N-BE(2)-C cell line cells. CPEC had an IC50 value of 100 nM for non-synchronised SK-N-BE(2)-C cells. These cells were arrested in G0/G1-phase or early S-phase of the cell cycle upon treatment with CPEC.