Alanine amino transferase (ALT) specific activities in long term systemic hypoxic rat brain tissues
Abstract
Background: Brain as a very aerobic organ is sensitive to hypoxia. Energy scarcities must be overcome by gluconeogenesis, which uses alanine or lactate as starting material. The reaction is catalyzed by alanine amino transaminase (ALAT or ALT), also known as glutamate pyruvate transaminase (GPT).
Objective: To investigate whether the specific activities of alanine aminotransferase (ALT) increased in hypoxic rat brain.
Methods: This experimental study used rats exposed to systemic normobaric hypoxia during 14 days. A group of 5 rats was sacrificed in days 1, 3, 7 and 14. The specific activities of ALT were analyzed in their brains using a reaction coupled with lactate dehydrogenase (LDH) activities.
Results: The ALT specific activities in rat brain were very low. There was no significant increase of specific activities during long term hypoxia (p > 0.05).
Conclusion: The rat brain ALT has no role in gluconeogenesis.
References
Cafaro R.P. Hypoxia, its causes and symptoms. J Am Dent Soc Anesthesiol. 1960;7: 4-8.
Acker T, Acker H. Cellular oxygen sensing need in CNS function: physiological and pathological implication. J Exp Biol. 2004;207: 3171-88. https://doi.org/10.1242/jeb.01075
Mergenthaler P, Lindauer U, Dienel GA, Meisel A. Sugar of the Brain: the role of glucose in physiological and pathological brain function. Trends Neurosci 2013; 10: 587-597. https://doi.org/10.1016/j.tins.2013.07.001
Moore JC, DeVries JW, Lipp M, Griffith JC, Abernethy DR. Total protein methods and their potential utility to reduce the risk of food protein adulteration. Comprehensive Reviews in Food Science and Food Safety. 2010;9:330-57. https://doi.org/10.1111/j.1541-4337.2010.00114.x
Porterfield J Z, Zlotnick A. A simple and general method for determining the protein and nucleic acid content of virus. Virology. 2010;407: 281-8. https://doi.org/10.1016/j.virol.2010.08.015
Whitaker JF. A general colorimetric procedure for estimation of enzymes which are linked to NADH/NAD+ system. Clin Chim Acta. 1069;24: 23-7. https://doi.org/10.1016/0009-8981(69)90137-5
Falkowska A, Gutowska I, Goschorska M, Nowacki P, Chlubek D, Baranowska-Bosiacka I. Energy metabolism of the Brain, including the cooperation between astrocytes and neurons, especially in the context of glycogen metabolism. Int J Mol Sci. 2015;16:25959-81. https://doi.org/10.3390/ijms161125939
Somers VK, Mark AL, Abboud FM. Circulatory regulation during hypoxia and hypercapnia, in: Arieff a. Hypoxia, metabolic acidosis and the circulation. Springer Link:3-20. https://doi.org/10.1007/978-1-4614-7542-2_1
Majmundar AJ, Wong JW, Simon MC. Hypoxia inducible factors and the responds to hypoxic stress. Molecular Cell. 2010;40:294-309. https://doi.org/10.1016/j.molcel.2010.09.022
Zagorska A, Dulak J. HIF-1: The knowns and unknowns hypoxia sensing. Acta Biochim Polon .2004;51: 563-85. https://doi.org/10.18388/abp.2004_3545
Ferdinal F, Suyatna FD, Wanandi SI, Sadikin M. Structural and morphological changes in rat ventricular myocardium induced by chronic systemic hypoxia. Acta Med Indonesiana. 2010;42: 135-41.
Jusman SWA, Iswanti FC, Suyatna FD, Ferdinal F, Wanandi SI, Sadikin M. Cytoglobin expression in oxidative stressed liver during systemic chronic normobaric hypoxia and relation with HIF-1. Med J Indones.2014;23:133-8. https://doi.org/10.13181/mji.v23i3.1025
Syarifin ANK, Jusman SWA, Sadikin M. Gene expression and enzymes activities of carbonic anhydrase and gloutaminase in rat kidneys indiced by chronic systemic hypoxia? Med J Indones 2015;24: 139-45. https://doi.org/10.13181/mji.v24i3.1190
Syam AF, Sadikin M, Wanandi SI, Rani AA. Molecular mechanism of healing process of peptic ulcer. Acta Med Indones. 2009;41: 95-8.
Hendrawan S, Jusman SWA, Ferdinal F, Prijanti AR, Wanandi SI, Sadikin M. Expression of hypoxia inducible factor-1 (HIF-) gene and apoptosis in the heart induced by systemic hypoxia. Med J Indones. 2009;18: 97-101. https://doi.org/10.13181/mji.v18i2.344
Fauquier DA, Mazet JAK, Gulland FMD, Spraker TR, Christopher MM. Distribution of tissues enzymes in three species of pinnipeds. J Zoo and Wildlife Med.2008;39:1-5. https://doi.org/10.1638/2006-0012.1
Yang RZ, Park S, Reagan WJ, Goldstein R, Zhong S, Lawton M, Rajamohan F, Qian K, Liu L, Gong DW. Alanine amino transferase isoenzymes: Molecular cloning and quantitative analysis of tissue expression in rats and serum elevation in liver toxicity. Hepatology. 2009;49: 598-607. https://doi.org/10.1002/hep.22657
Brosnan JT. Interorgan amino acid transport and its regulation. J Nutr.2003;133:2068S-72S. https://doi.org/10.1093/jn/133.6.2068S
Engelking LR. Text Book of Veterinary Physiological Chemistry. 3th ed. Academic Press; 2015. Chapter 37, Gluconeogenesis, ; p.225-230. https://doi.org/10.1016/B978-0-12-391909-0.50037-2
Snell K. Alanine as gluconeogenic carrier. Trend in Biochem Sci.1979;4: 124-8. https://doi.org/10.1016/0968-0004(79)90442-0
Yip J, Geng XK, Shen JM, Ding YC. Cerebral gluconeogenesis and diseases. Frontiers in Pharmacology.2017;7: 1-12. https://doi.org/10.3389/fphar.2016.00521
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