Anoxia tolerance

Krumschnabel, G., Schwarzbaum, P. J., Lisch, J., Biasi, C. and Wieser, W. (2000). Oxygen-dependent energetics of anoxia-tolerant and anoxia intolerant hepatocytes, J. Exp. Biol., 203, 951-959. 

Hylland, P., S. Milton, M. Pek, G.E. Nilsson, and P.L. Lutz (1997). Brain Na+/K+-ATPase activity in two anoxia tolerant vertebrates crucian carp and freshwater turtle. Neurosci. Lett. 235 89-92. 

Land, S.C., and P.W. Hochachka (1995). A heme-protein based oxygen sensing mechanism controls the expression and suppression of multiple proteins in anoxia tolerant turtle hepatocytes. Proc. Natl. Acad. Sci. USA 92 7505-7509. 

Land, S.C, L.T. Buck, and P.W. Hochachka (1993). Response of protein synthesis to anoxia and recovery in anoxia-tolerant hepatocytes. Am. J. Physiol. 265 R41-R48. 

CNS of anoxia-tolerant reptiles contrasted with levels in anoxia-intolerant species. /. Neurochem. 64 1790-1799. 

Braendle, R., and R. M. M. Crawford. 1987. Rhizome anoxia tolerance and habitat specialization in wedand plants. In Plant Life in Aquatic and Amphibious Habitats. Special Publication Number 5 of the British Ecological Society, ed. R. M. M. Crawford (Blackwell Scientific Publications, Oxford), pp. 397-410. 

It is clear that the closure of voltage-gated K" " charmels by hypoxic exposure has implications for neuroprotection as demonstrated by K+ channel arrest in hypoxia-tolerant turtles (Pek and Lutz, 1997 Bidder and Buck, 1998 Hochachka and Lutz, 2001 Bidder and Donohoe, 2002), which reduces Ca" influx (Bidder and Buck, 1998). In some anoxia-tolerant spedes, neuronal energy is not only conserved by ion channel arrest but also by ATP-sensitive mitochondrial K+ channel arrest (reviewed by Buck and Pamenter, 2006). This may have implications for chnical interventions. 

Hochachka PW, Lutz PL. 2001. Mechanism, origin, and evolution of anoxia tolerance in animals. Comp Biochem Physiol B Biochem Mol Biol 130 435-459. 

Oxygen-dependent energetics of anoxia-tolerant and anoxia-intolerant hepatocytes. J Exp Biol 203 951-959. 

Milton SL, Nayak G, Lutz PL, Prentice HM. 2006. Gene transcription of neuroglobin is upregulated by hypoxia and anoxia in the brain of the anoxia-tolerant turtle Tra-chetnys seripta. J Biomed Sci 13 509-514. 

Figure 6. Variations on phosphoenolpyruvate (PEP) and pyruvate (PYR) metabolism in animals. In mammalian liver, pyruvate kinase (PK) and PEP carboxykinase (PEPCK) function in opposite directions to support glycolysis versus gluconeogenesis. In anoxia-tolerant mollusks, PEP is routed via PK when oxygen is present and via PEPCK in anoxia. Note that PEPCK is adapted for physiological function in opposite directions in the two situations.

Brooks, S. P. J. Storey, K. B. (1990). A cGMP stimulated protein kinase phosphorylates pyruvate kinase in an anoxia tolerant marine mollusk. J. Comp. Physiol. B 160,309-316. 

Haddad GG. Mechanisms of anoxia tolerance a novel approach using a Drosophila model system. In Hudetz, Bruley, eds. Oxygen Transport to Tissue XX. New Vbrk Plenum Press, 1998 273-280. 

In addition to turtles, the goldfish Carassius auratus) and the crucian carp Carassius carassius) are among the few vertebrates with substantial anoxia tolerance. Carp can survive days of anoxia at room temperature, and if the... 

Figure 3. Relationship between the fractional depression of heat dissipation under anoxia and anoxia tolerance (expressed as 1/median mortality time in hours) for larvae and juveniles of Crassostrea virginica [redrawn from II].

Mytilus edulis larvae [33]. The trend was similar for M. edulis larvae regarding the increased anoxia tolerance in later developmental forms, as was the recovery profiles for CR ratios. However, there was a significant anaerobic component in the total energy expenditure of larvae under normoxic conditions (Table 1), which the authors suggested was due to periods of valve closure and quiescence under normoxia that diminished under moderate hypoxia. In addition to calorimetric data on M edulis larvae, measurements are also available for gametes [98]. These data showed that mass-specific heat dissipation increased five-fold as development proceeded from the unfertilized egg to the D-stage (3-day) larva, but then declined thereafter. 

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