International Union for Circumpolar Health Ministry of Public Health and Social Development of RF Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Medical Sciences Siberian Branch of Russian Academy of Sciences Medical Polar Fund “Science” The Northern Forum

Abstracts

Performance and Health in Cold Climate

Introduction: Cold adaptation can decrease the efficiency of tissue and organ functions. This fact is established for heart and skeleton musculature. The role of liver in adaptive process at cold exposure is known unsufficiently.

Study design: The purpose of the present work was the analysis of effect long-term cold exposure on liver monooxygenase system and phases I and II of xenobiotics metabolism.

Methods: The alterations in pharmacokinetics of antipyrine and isoniazide and in vitro liver microsomal metabolic capacity were studied on Wistar male rats in Hart model during 7 weeks of cold acclimation

Results: The acceleration of elimination of antipyrine and isoniazide on the 10th - 15th days of cold exposure were detected, testifying the enhancement of activity of both I, and II phases of biotransformation. The rate of metabolism of drugs returned to a reference level to the end of study. Total content of cytochrome Р450 and activity of NADP•H-cytochrome (Р450) reductase were increased and reached a maximum (about 200% vs control) on the 15th day with the subsequent decrease. Cold exposure considerably changed the microsomal metabolism of cytochrome Р450-isoenzymes specific substrates.

Conclusion: The acceleration of drugs elimination testifies against depression of a metabolic function of a liver in Hart model of cold acclimation. The cold exposure modifies a spectrum of cytochromes Р450 and monooxyganase activity. The biological significance and possible consequences of this phenomenon should be studied.

Note. Abstracts are published in author's edition

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Last update: 06-Jul-2012 (11:52:05)