Metabolism of reduced pyridine nucleotides in ascites cell nuclei

The Effect of Cytostatic Drugs on the Metabolic Response of Ascites Tumor Cells

“…The microfluorimetric-microelectrophoretic technique (KOHEN, KOHEN & JENKINS I966), the ascites tumor tissue culture cells (EL2 cells, cf. KOHEN 1964;KOHEN, SIEBERT & KOHEN 1964) and the X-ray produced EL2 giants (ELZG cells, cf. KOHEN, KOHEN & JENKINS 1966), the estimates relative to the amounts of substrates or metabolites introduced into the cytoplasm of single living cells (roughly 10-14 mole substrate/lO BPI cell volume) and the actual concentrations of reduced pyridine nucleotide reached in these cells have been described elsewhere (KOHEN, KOHEN & JENKINS 1966;KOHEN, KOHEN & THORELL 1968b & c).…”

“…Since the fluorescence of reduced pyriding nucleotides sharply depends on the nature and quality of their binding (ESTABROOK 1962). it seems necessary to validate the fluorescence measurements by direct extraction and assay of reduced pyridine nucleotide (BORST & COLPA-BOONSTRA 1962; MAITRA & CHANCE 1965) and calibration of these results with the intracellular conditions of fluorescence (KOHEN, SIEBERT & KOHEN 1964;MAITRA & CHANCE 1965). Comparative fluorescence measurements between intracellular pyridine nucleotides and a glass capillary standard filled with a known solution of reduced pyridine nucleotides are made (KOHEN, LEGALLAIS & KOHEN 1966).…”

Enzymology of the Nucleus

“…Since the nucleus is devoid of a complete respiratory chain (23), a reoxidation of glycolytically formed DPNH must take place outside the nucleus and most likely occurs through a mechanism which is similar to%hat by which cytoplasmic DPNH is reoxidized (see also ref. 86). Even large molecules such as messenger RNA must find their way to pass the nuclear membrane (87,88).…”

“…(3) During glycolysis, microfluorimetry of ascites cells demonstrates a delayed reoxidation of nuclear DPNH (86), when compared with the cytoplasmic DPNH, after acrobiosis. (4) A part of the inorganic 32P which is taken up by isolated rat liver nuclei is found in polyphosphate (93) whose further metabolic fate is yet unknown.…”