Abstract
Glucose and lipid metabolism in the brain, liver and in a transplanted tumour were found to be variously altered within 2 to 3 h of administering single doses of the radiosensitizer Ro-03-8799 to normal and tumour-bearing mice. Hepatic lactate and glycerol-3-phosphate (G3P) levels were decreased but those of the ketone body beta-hydroxybutyrate (beta-HOBu) were raised. However, in the tumour, these levels were all enhanced. The lactate levels in brain remained relatively constant but both beta-HOBu and G3P levels were altered in a manner similar to that in the liver. The levels of glucose were approximately doubled in blood, brain and tumour, but whereas tumour G6P levels increased, those in the brain were lowered to below the limits of detection. Hepatic glucose levels were significantly decreased after 1 h but G6P levels were not affected. These changes could neither be related to inhibitory effects on hepatic glucokinase or brain hexokinase activity nor to limiting amounts of ATP in both tissues. However, the activity of glucose-6-phosphatase (G6P'ase) was distinctly raised in the liver and the hepatic glycogen stores were also rapidly lowered. Overall, the results suggest that Ro-03-8799 exerts a stimulatory effect on glucose production in the liver. In both liver and brain the levels of free fatty acids and phospholipids were increased whereas those of esterified fatty acids were lowered. Most importantly, the changes in metabolite levels affect the cellular redox couples; those of the cytosol (lactate/pyruvate; G3P/dihydroxyacetone phosphate (DAP] are directed towards the oxidised state in the liver but to a more reduced state in the tumour. The mitochondrial couple (beta-HOBu/acetoacetate (AcAc)) in both tissues is shifted towards the reduced state. These metabolic changes may result in an increase in the degree of hypoxia in the tumour and may well play an important role in the development of neuropathies.
Full text
PDF





Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Adams G. E. Hypoxia-mediated drugs for radiation and chemotherapy. Cancer. 1981 Aug 1;48(3):696–707. doi: 10.1002/1097-0142(19810801)48:3<696::aid-cncr2820480307>3.0.co;2-v. [DOI] [PubMed] [Google Scholar]
- Caldwell J. Novel xenobiotic-lipid conjugates. Biochem Soc Trans. 1985 Oct;13(5):852–854. doi: 10.1042/bst0130852. [DOI] [PubMed] [Google Scholar]
- Chin J. B., Rauth A. M. The metabolism and pharmacokinetics of the hypoxic cell radiosensitizer and cytotoxic agent, misonidazole, in C3H mice. Radiat Res. 1981 May;86(2):341–357. [PubMed] [Google Scholar]
- Coleman C. N., Hirst V. K., Brown D. M., Halsey J. The effect of vitamin B6 on the neurotoxicity and pharmacology of desmethylmisonidazole and misonidazole: clinical and laboratory studies. Int J Radiat Oncol Biol Phys. 1984 Aug;10(8):1381–1386. doi: 10.1016/0360-3016(84)90353-5. [DOI] [PubMed] [Google Scholar]
- Coleman C. N. Hypoxic cell radiosensitizers: expectations and progress in drug development. Int J Radiat Oncol Biol Phys. 1985 Feb;11(2):323–329. doi: 10.1016/0360-3016(85)90154-3. [DOI] [PubMed] [Google Scholar]
- Crisp D. M., Pogson C. I. Glycolytic and gluconeogenic enzyme activities in parenchymal and non-parenchymal cells from mouse liver. Biochem J. 1972 Feb;126(4):1009–1023. doi: 10.1042/bj1261009. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dische S., Saunders M. I., Stratford M. R. Neurotoxicity with desmethylmisonidazole. Br J Radiol. 1981 Feb;54(638):156–157. doi: 10.1259/0007-1285-54-638-156. [DOI] [PubMed] [Google Scholar]
- Fowler J. F. Eighth annual Juan del Regato lecture. Chemical modifiers of radiosensitivity--theory and reality: a review. Int J Radiat Oncol Biol Phys. 1985 Apr;11(4):665–674. doi: 10.1016/0360-3016(85)90296-2. [DOI] [PubMed] [Google Scholar]
- Heimbrook D. C., Sartorelli A. C. Biochemistry of misonidazole reduction by NADPH-cytochrome c (P-450) reductase. Mol Pharmacol. 1986 Feb;29(2):168–172. [PubMed] [Google Scholar]
- Hill S. A., Fowler J. F., Minchinton A. I., Stratford M. R., Denekamp J. Radiosensitization of a mouse tumour by Ro 03-8799: acute and protracted administration. Int J Radiat Biol Relat Stud Phys Chem Med. 1983 Aug;44(2):143–150. doi: 10.1080/09553008314550941. [DOI] [PubMed] [Google Scholar]
- Hutson D. H., Dodds P. F., Logan C. J. The significance of xenobiotic-lipid conjugation. Biochem Soc Trans. 1985 Oct;13(5):854–856. doi: 10.1042/bst0130854. [DOI] [PubMed] [Google Scholar]
- Jones A. V., Harwood J. L., Stratford M. R., Stumpf P. K. Inhibition of plant fatty acid synthesis by nitroimidazoles. Biochem J. 1981 Jul 15;198(1):193–198. doi: 10.1042/bj1980193. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McGarry J. D., Foster D. W. Regulation of hepatic fatty acid oxidation and ketone body production. Annu Rev Biochem. 1980;49:395–420. doi: 10.1146/annurev.bi.49.070180.002143. [DOI] [PubMed] [Google Scholar]
- Millar B. C. Hypoxic cell radiosensitizers as potential adjuvants to conventional chemotherapy for the treatment of cancer. Biochem Pharmacol. 1982 Aug 1;31(15):2439–2445. doi: 10.1016/0006-2952(82)90051-x. [DOI] [PubMed] [Google Scholar]
- Raleigh J. A., Franko A. J., Koch C. J., Born J. L. Binding of misonidazole to hypoxic cells in monolayer and spheroid culture: evidence that a side-chain label is bound as efficiently as a ring label. Br J Cancer. 1985 Feb;51(2):229–235. doi: 10.1038/bjc.1985.33. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roberts J. T., Bleehen N. M., Walton M. I., Workman P. A clinical phase I toxicity study of Ro 03-8799: plasma, urine, tumour and normal brain pharmacokinetics. Br J Radiol. 1986 Feb;59(698):107–116. doi: 10.1259/0007-1285-59-698-107. [DOI] [PubMed] [Google Scholar]
- Siemann D. W. Potentiation of chemotherapy by hypoxic cell radiation sensitizers--a review. Int J Radiat Oncol Biol Phys. 1982 Jun;8(6):1029–1034. doi: 10.1016/0360-3016(82)90172-9. [DOI] [PubMed] [Google Scholar]
- Stratford M. R., Minchinton A. I., Hill S. A., McNally N. J., Williams M. V. Pharmacokinetic studies using multiple administration of RO 03-8799, a 2-nitroimidazole radiosensitizer. Int J Radiat Oncol Biol Phys. 1982 Mar-Apr;8(3-4):469–471. doi: 10.1016/0360-3016(82)90663-0. [DOI] [PubMed] [Google Scholar]
- Tamulevicius P., Streffer C., Blanke G., Luscher G. The effects of radiosensitizers on intermediary metabolism in vivo. Int J Radiat Oncol Biol Phys. 1984 Aug;10(8):1387–1389. doi: 10.1016/0360-3016(84)90354-7. [DOI] [PubMed] [Google Scholar]
- Varghese A. J., Whitmore G. F. Detection of a reactive metabolite of misonidazole in human urine. Int J Radiat Oncol Biol Phys. 1984 Aug;10(8):1361–1363. doi: 10.1016/0360-3016(84)90349-3. [DOI] [PubMed] [Google Scholar]
- Workman P. Dose-dependence and related studies on the pharmacokinetics of misonidazole and desmethylmisonidazole in mice. Cancer Chemother Pharmacol. 1980;5(1):27–37. doi: 10.1007/BF00578559. [DOI] [PubMed] [Google Scholar]
