In our previous studies we have found both an increase of lipid peroxidation damage (expressed as levels of thiobarbituric acid-reactive substances) in brain and plasma lactate concentration in 21-day-old rats after a 30-min exposure to hypobaric hypoxia. Pretreatment of rats with L-carnitine decreased both parameters. The aim of our present study was to determine if the L-carnitine-dependent decrease of plasma lactate could be due to a modification of lactate dehydrogenase (LDH) activity. We followed brain and blood serum LDH activity of 14-, 21- and 90-day-old Wistar rats. We found an increase of brain LDH activity with age. However, we did not observe any significant differences in LDH activity after exposure to hypobaric hypoxia or L-carnitine pretreatment. In contrast to brain, serum LDH activity did not show any clear age-dependence. The hypoxia exposure increased LDH activity of 21-day-old rats only. Pretreatment of rats with L-carnitine decreased serum LDH activity of 21- and 90-day-old rats probably due to membrane stabilizing role of L-carnitine. In conclusions, acute hypobaric hypoxia and/or L-carnitine pretreatment modified serum but not brain LDH activity.

• MeSH
• hypoxie enzymologie   MeSH
• krysa rodu Rattus MeSH
• L-laktátdehydrogenasa krev   metabolismus   MeSH
• mozková kůra enzymologie   MeSH
• potkani Wistar MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• L-laktátdehydrogenasa MeSH

The exposure to hypobaric hypoxia increased lipid peroxidation as indicated by thiobarbituric acid-reactive substances [TBARS] in rat brain. Plasma lactate/pyruvate ratio was used as a marker of hypoxia. We compared the protective effect of alpha-tocopherol with the effect of L-carnitine or phosphocreatine. Rats pretreated with alpha-tocopherol, L-carnitine, or phosphocreatine had lower TBARS levels after the exposure to hypobaric hypoxia. However, lactate/ pyruvate ratio was improved only in rats pretreated with L-carnitine or phosphocreatine. We conclude from our data that, contrary to alpha-tocopherol, protective effects of L-carnitine and phosphocreatine administrations are due to their regulation of metabolic reactions during hypobaric hypoxia rather than to their scavenger activity.

• MeSH
• fosfokreatin farmakologie   MeSH
• hypoxie metabolismus   MeSH
• karnitin farmakologie   MeSH
• krysa rodu Rattus MeSH
• látky reagující s kyselinou thiobarbiturovou metabolismus   MeSH
• mozek účinky léků   metabolismus   MeSH
• peroxidace lipidů * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fosfokreatin MeSH
• karnitin MeSH
• látky reagující s kyselinou thiobarbiturovou MeSH