Pflügers Archiv

, Volume 425, Issue 1–2, pp 22–27 | Cite as

Effects of acidic stimuli on intracellular calcium in isolated type I cells of the neonatal rat carotid body

  • K. J. Buckler
  • R. D. Vaughan-Jones
Molecular and Cellular Physiology


We have investigated the effects of acidic stimuli upon [Ca2+]i in isolated carotid body type I cells from the neonatal rat using indo-1 (AM-loaded). Under normocapnic, non-hypoxic conditions (23 mM HCO3, 5% CO2 in air, pHo=7.4), the mean [Ca2+]i for single cells was 102±5.0 nM (SEM, n=55) with 58% of cells showing sporadic [Ca2+]i fluctuations. A hypercapnic acidosis (increase in CO2 to 10%–20% at constant HCO3, pHo 7.15–6.85), an isohydric hypercapnia (increase in CO2 to 10% at constant pHo=7.4) and an isocapnic acidosis (pHo=7.0, constant CO2) all increased [Ca2+]i in single cells and cell clusters. The averaged [Ca2+]i response to both hypercapnic acidosis and isohydric hypercapnia displayed a rapid rise followed by a secondary decline. The averaged [Ca2+]i response to isocapnic acidosis displayed a slower rise and little secondary decline. The rise of [Ca2+]i in response to all the above stimuli can be attributed to no single factor other than to a fall of pHi. The hypercapnia-induced rise of [Ca2+]i was almost completely abolished in Ca2+-free solution, suggesting a role for Ca2+ influx in triggering and/or sustaining the [Ca2+]i response. These results are consistent with a role for type I cell [Ca2+]i in mediating pH/PCO2 chemoreception.

Key words

Carotid body Chemoreceptor Intracellular calcium Intracellular pH Extracellular pH Acidosis Hypercapnia 


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Copyright information

© Springer-Verlag 1993

Authors and Affiliations

  • K. J. Buckler
    • 1
  • R. D. Vaughan-Jones
    • 1
  1. 1.University Laboratory of PhysiologyUniversity of OxfordOxfordUK

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