Cobalt supplementation promotes hypoxic tolerance and facilitates acclimatization to hypobaric hypoxia in rat brain

High Alt Med Biol. 2008 Spring;9(1):63-75. doi: 10.1089/ham.2008.1046.

Abstract

In the present study, we report the molecular mechanisms of action by cobalt in facilitating acclimatization to hypobaric hypoxia using male Sprague-Dawley rats as the model system. We determined hypoxic gasping time and survival time as a measure to assess the degree of tolerance of animals to hypobaric hypoxia by exposing the animals to an altitude of 10,668 m. Oral administration of cobalt chloride (12.5 mg Co/kg body weight, BW, for 7 days) increased gasping time and hypoxic survival time by 3 to 4 times compared to the control animals. This could be attributed to an increased expression and the DNA binding activity of hypoxia inducible transcriptional factor (HIF-1alpha) and its regulated genes, that is, erythropoietin (EPO), vascular endothelial growth factor (VEGF), glucose transporter-1 (Glut-1), and nitric oxide synthase (NOS) levels. This in turn leads to better oxygenation, oxygen delivery, glucose transport, and maintenance of vascular tone, respectively, under oxygen-limited conditions. This was further confirmed by lower levels of lactate dehydrogenase (LDH) activity and lactate in the brain of cobalt + hypoxia group compared with animals exposed to hypoxia. Glucose levels also increased after cobalt supplementation. The findings of the study provide a basis for the possible use of cobalt for facilitating acclimatization to hypoxia and other conditions involving oxygen deprivation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acclimatization / drug effects*
  • Adaptation, Physiological / drug effects
  • Altitude Sickness / complications
  • Altitude Sickness / metabolism*
  • Altitude Sickness / prevention & control*
  • Animals
  • Cobalt / administration & dosage
  • Cobalt / pharmacology*
  • Erythropoietin / metabolism
  • Glucose Transporter Type 1 / metabolism
  • Hypoxia, Brain / etiology
  • Hypoxia, Brain / metabolism*
  • Hypoxia, Brain / prevention & control*
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Male
  • Nitric Oxide Synthase / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Species Specificity
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Glucose Transporter Type 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Vascular Endothelial Growth Factor A
  • Erythropoietin
  • Cobalt
  • Nitric Oxide Synthase
  • cobaltous chloride