Control of ventilation in the hypercapnic skate Raja ocellata: I. Blood and extradural fluid

M. S. Graham, J. D. Turner, C. M. Wood

Research output: Contribution to journalArticlepeer-review

86 Scopus citations


In order to study the role of CO2 and acid-base status in contributing to ventilatory drive, skate were exposed to normoxic hypercapnia (PICO2 = 7.5 Torr) under conditions where the primary O2 drive a small Bohr effect. Red blood cell pHi was not preferentially regulated, and there was no evidence of RBC swelling or nucleoside triphosphate adjustment. Although there were no changes in arterial O2 levels during hypercapnia, ventilation immediately increased 2.7-fold through large changes in stroke volume and small changes in frequency, and declined only slightly through 24-48 h. PaCO2 equilibrated rapidly with PICO2, driving down arterial pHa, which was 65% corrected through HCO3- accumulation by 24 h. In contrast, the extradural fluid outside the brain equilibrated only very slowly, and was clearly not involved in the ventilatory stimulation. Increased ventilation during hypercapnia may be related to depressions in pHa.

Original languageEnglish (US)
Pages (from-to)259-277
Number of pages19
JournalRespiration Physiology
Issue number2-3
StatePublished - 1990
Externally publishedYes


  • Animal, skate
  • Blood, O transport properties in skate
  • Bohr effect in skate
  • Cerebrospinal fluid, acid-base balance
  • Control of breathing, cerebrospinal fluid in skate, response to CO
  • Hypercapnia, ventilatory response in skate
  • pH, intracellular
  • Red cell, intracellular pH in skate
  • Ventilation, sensitivity to CO in skate

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine


Dive into the research topics of 'Control of ventilation in the hypercapnic skate Raja ocellata: I. Blood and extradural fluid'. Together they form a unique fingerprint.

Cite this