Role of Cl--HCO3- Exchanger and Anion Channel in the Cat Carotid Body Function
Carotid body (CB) chemosensory responses to respiratory and metabolic acidosis are well demonstrated both in vivo and in vitro 1. The responses are expected to originate from the chemoreceptor cells which usually should manifest parallel phenomena. The consensus model of the chemoreceptor unit is that the glomus cells are the presynaptic chemoreceptor cells and the sensory fibers are the postsynaptic elements which, we supposed, should reflect the events in the presynaptic glomus cells. However, Buckler et al.2 and Wilding et al.3 reported that the glomus cells possessed at least three ion-exchangers which regulated the intracellular pH (pHi). If the chemosensory responses are coupled to the pHj of the glomus cell and its pHi is well regulated then there will be a lack of correspondence between the glomus cell pHi and the sensory response to CO2-H+. Accordingly the role of the ion-exchangers would appear ambivalent.
KeywordsCarotid Body Glomus Cell Carotid Sinus Nerve Chemosensory Response Chemoreceptor Cell
Unable to display preview. Download preview PDF.
- 1.C. Eyzaguirre, R. S. Fitzgerald, S. Lahiri, and P. Zapata, Arterial Chemoreceptors, in: Handbook of Physiology. The Cardiovascular System, Peripheral Circulation and Organ Flow, American Physiol Soc, Williams and Wilkins, Baltimore, p. 557–621 (1983).Google Scholar
- 3.T. J. Wilding, B. Cheng, and A, Roos, The relationship between extracellular pH (pHo) and intracellular pH (pHi) in adult rat carotid body glomus cells, Biophys. J., 59: 184a (1991).Google Scholar
- 4.A. Roos, and W.F. Boron, Intracellular pH, Physiol Rev., 61: 296–434 (1984).Google Scholar
- 9.R. Iturriaga, W.L. Rumsey, S. Lahiri, D. Spergel, and D.F. Wilson, Intracellular pH and O2 chemoreception in the cat carotid body, J. Appl. Physiol., 72: (1992). (In press).Google Scholar