TY - JOUR
T1 - Preliminary examination of the influence of incubation time or cytosolic protein concentration on dihydropyrimidine dehydrogenase activity
AU - Tateishi, Tomonori
AU - Nakura, Hironori
AU - Watanabe, Minoru
AU - Tanaka, Masami
AU - Kumai, Toshio
AU - Kobayashi, Shinichi
PY - 1996/8/15
Y1 - 1996/8/15
N2 - We examined the influence of incubation time or cytosolic protein concentration on the metabolite production of 5-fluorouracil (5FU). Although the activity of dihydropyrimidine dehydrogenase (DPDase) from rat liver is considered to be retained for up to 60 min, the production rate of 5FU metabolites was reduced, probably due to depletion of the substrate in 40 μmol/l and lower concentration of 5FU. Since the ratio of the metabolite production rate to the cytosolic protein became smaller in higher concentrations of cytosolic protein, the DPDase activity should be compared in the same concentration of cytosolic protein. The production rate of 5FU metabolites was considered to be linear up to 40 μmol/l 5FU incubated with 500 μg cytosolic protein. The rate of the metabolite production calculated by one-point sampling significantly correlated with the enzyme activity by the multi-point sampling method. Minimizing sampling points to determine the DPDase activity would save time and expense.
AB - We examined the influence of incubation time or cytosolic protein concentration on the metabolite production of 5-fluorouracil (5FU). Although the activity of dihydropyrimidine dehydrogenase (DPDase) from rat liver is considered to be retained for up to 60 min, the production rate of 5FU metabolites was reduced, probably due to depletion of the substrate in 40 μmol/l and lower concentration of 5FU. Since the ratio of the metabolite production rate to the cytosolic protein became smaller in higher concentrations of cytosolic protein, the DPDase activity should be compared in the same concentration of cytosolic protein. The production rate of 5FU metabolites was considered to be linear up to 40 μmol/l 5FU incubated with 500 μg cytosolic protein. The rate of the metabolite production calculated by one-point sampling significantly correlated with the enzyme activity by the multi-point sampling method. Minimizing sampling points to determine the DPDase activity would save time and expense.
KW - 5-Fluorouracil
KW - Cytosolic protein
KW - Dihydropyrimide dehydrogenase
KW - Incubation time
KW - Substrate concentration
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U2 - 10.1016/0009-8981(96)06315-2
DO - 10.1016/0009-8981(96)06315-2
M3 - Article
C2 - 8814356
AN - SCOPUS:0030586973
VL - 252
SP - 1
EP - 9
JO - Clinica Chimica Acta
JF - Clinica Chimica Acta
SN - 0009-8981
IS - 1
ER -