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THE HEXOSE MONOPHOSPHATE PATHWAY IN ETHYLNITROSOUREA INDUCED TUMORS OF THE NERVOUS SYSTEM
Author(s) -
Coleman Mary Thoesen,
Allen Norman
Publication year - 1978
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1978.tb07038.x
Subject(s) - ethylnitrosourea , hexose , central nervous system , medicine , endocrinology , chemistry , biology , isolated brain , in vitro , enzyme , biochemistry , mutant , gene
— Respiration studies in vitro , in which tissue slices were incubated with [1‐ 14 C]glucose or [6‐ 14 C]glucose and 14 CO 2 collected, resulted in C‐1/C‐6 14 CO 2 ratios that were higher in slices of tumor and newborn brain than in slices of adult brain. In adult brain, the C‐1/C‐6 14 CO 2 ratio averaged close to unity. In slices of tumor and newborn brain however, the mean C‐1/C‐6 ratio was greater than three. Addition of phenazine methosulfate (PMS) increased conversion of [1‐ 14 C]glucose to 14 CO 2 in slices of normal adult brain 5‐fold, and in slices of newborn brain and tumor, approx 12‐fold. Injection of animals with 6‐aminonicotinamide (6‐AN) decreased conversion of [1‐ 14 C]glucose in slices of normal brain 30% but decreased conversion in tumor slices by 80%. Evidence supports the presence of an active hexose monophosphate pathway (HMP) in tumors of the nervous system regulated in part by available NADP + levels. Inhibition by 6‐AN was more effective in tumors than in normal adult brain.