Oxidative Stress Poster Session

Re: Poster 0410 (K. Cowan) Anoxia Effects ... O. Virilis

Dr. Kyra J. Cowan

On Thu Dec 10, S. Reading wrote
>You have an interesting poster and a fascinating organism to study. My question probably reflects my lack of understanding of invertabrate metabolism but here it is. I am unclear on a statment made in the discussion where you indicate that there is a, "switching of most organs to a primary dependence on lipid oxidation.". I am curious to know if this organism has the capacity to metabolize lipids in the absence of oxygen? Second, the use of glycerol to sustain gluconeogenesis would result in the accumulation of FFA's. Assuming that O. Virilis cannot metabolize them anaerobically, how does O. Virilis deal with FFA toxicity ? I look forward to your answer and I hope you enjoy the conference.

>S. Reading  

RE: Dr.Reading’s questions

Dear Dr. Reading

Thanks for your questions. During anoxia, lipids cannot be oxidized as this requires the TCA cycle to function. Rather, during anoxia, many lower vertebrates and invertebrates MAKE and elongate lipids (for example, this happens in the carp during the long Russian winter). During anoxia these invertebrates ferment carbohydrates – so the switching of lipid fuel was meant to be when the RECOVER from anoxia! However, free fatty acid toxicity does not occur in the anaerobic fishes as the FFA’s are immediately sucked up into triglycerides and phospholipids. The fate of FFA’s during hypoxia or anoxia in invertebrates is largely unknown.

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