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An Unusual Cytochrome a592 with Low PO2 Affinity correlates with Afferent Discharge in the Carotid Body

  • Christine Huckstorf
  • Tino Streller
  • Helmut Acker
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 536)

Abstract

The carotid body (CB) located at the carotid artery bifurcation informs the central nervous system about arterial p02 changes. The CB response to hypoxic stimuli includes augmented transmitter release and increased generation of action potentials in the carotid sinus nerve (CSN). Until now the molecular and cellular mechanisms of the oxygen sensing signal cascade are not clear. Cellular oxygen sensing processes are believed to be initiated by specialised cytochromes (Bunn and Poyton, 1996; Lopez-Barneo et al. 2001). In recent studies (Lahiri and Acker, 1999; Lahiri et. al 1999) simultaneous recordings of rat CB light absorption spectra and chemoreceptor discharge were used to characterize heme proteins as primary oxygen sensor. Redox spectra were deconvoluted by means of redox differential spectra of isolated non mitochondrial cytochrome b558 and mitochondrial cytochromes c550, b563 and the cytochrome c oxydase (CCO) peaking at 603 nm. Mathematically deconvolution fitted very closely to experimental spectra in the wavelength range between 520 and 570 nm confirming the contribution of cytochromes b558, c550 and b563 in the carotid body tissue. However, the wavelength range between 570 and 620 nm normally dominated by cytochrome aa3 of the CCO (absorbance peak at 603 nm) was fitted only partly indicating an additional component.

Keywords

Carotid Body Spectral Weight Tonic Component Carotid Sinus Nerve Carotid Artery Bifurcation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Bunn, H.F., and Poyton, R.O., 1996, Oxygen sensing and molecular adaptation to hypoxia., Physiol Rev. 76: 839–885PubMedGoogle Scholar
  2. Lopez-Barneo, J., Pardal, R., and Ortega-Saenz, P., 2001, Cellular mechanism of oxygen sensing., Ann. Rev. Physiol. 63: 259–287CrossRefGoogle Scholar
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  5. Streller, T., Huckstorf, C., Pfeiffer, C., and Acker, H. 2002, Unusual cytochrome a592 with low P02 affinity correlates as putative oxygen sensor with rat carotid body chemoreceptor discharge, FASEB J 16: 1277–1279Google Scholar

Copyright information

© Springer Science+Business Media New York 2003

Authors and Affiliations

  • Christine Huckstorf
    • 1
  • Tino Streller
    • 1
  • Helmut Acker
    • 2
  1. 1.Institute of PhysiologyUniversity of RostockGermany
  2. 2.Max-Planck-Institute of Molecular PhysiologyOtto-Hahn-StrGermany

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