Aerobic Glycolysis in the Retina of the Crab Ocypode Ryderi
Higher crustaceans (Malacostracan) possess compound eyes of a similar type as insects (apposition eyes). They consist of several thousands of ommatidia, each composed of a cornea followed by the dioptric apparatus and the long visual receptor cells (500 μm), which contain the light-sensitive rhabdoms and are enveloped by the pigment cells and separated from each other by a large extracellular space. The axons of the receptor cells penetrate the basal lamina to contact the optical ganglia. Since insect eyes are supplied with sufficient oxygen by tracheols, their metabolism is exclusively aerobic (Tsacopoulos et al., 1981). In contrast, the retina of crustaceans is supplied with oxygen by haemolymph in a similar way as the mammalian retina by blood, which is known to perform aerobic glycolysis (Warburg et al., 1924). Therefore, to investigate the metabolism of the crab retina and see whether aerobic glycolysis also exists, we measured tissue Po2 (PgO2) and extracellular pH (pHe) under normoxic and hypoxic conditions and determined lactate production.
KeywordsBasal Lamina Aerobic Glycolysis Mammalian Retina Optical Ganglion Lucite Chamber
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- Delpiano, M. A., Knollmann, U., Acker, H., and Langer, H., 1989, PO2 and pH in the retina of the crab Ocypode ryderi — Evidence for aerobic glycolysis (in preparation).Google Scholar
- Langer, H., Delpiano, M. A., Knollmann, U., and Acker, H., 1988, Oxygen and and glycolysis in the retina of the compound eye of a crab, in: “Oxygen Sensing in Tissues,” H. Acker, ed., Springer-Verlag, Berlin.Google Scholar
- Lowry, O. H., and Passoneau, J. V., 1972, “A Flexible System of Enzymatic Analysis,” Academic Press, New York.Google Scholar
- Morris, S., and Bridges, C. R., 1985, An investigation of haemocyanin oxygen affinity in the semi-terrestrial crab Ocypode saratan Forsk, J. Exp. Biol., 117:119.Google Scholar
- Rivera, M. E., and Langer, H., 1983, Enzyme pattern of energy releasing metabolism in eyes, optical ganglia of the blowfly Calliphora erythrocephala and the crab Ocypode ryderi, Mol. Physiol., 4:265.Google Scholar
- Warburg, O., Posener, K., Negelein, E., 1924, Über den Stoffwechsel der Carcinomzelle, Biochem. Z., 152:309.Google Scholar