Control of ventilation in the hypercapnic skate Raja ocellata: II. Cerebrospinal fluid and intracellular pH in the brain and other tissues
Abstract
This study examined the possible role(s) of central acid-base stimuli in the increase in ventilation induced by hypercapnia in the skate, a response that is not due to an O2 signal (Graham et al., Respir. Physiol., 1990, 80: 251-270). Skate were sampled for cerebrospinal fluid (CSF) acid-base status, intracellular pH of the brain (14C-DMO method), and pHi in other tissues throughout 24 h of exposure to PICO2 = 7.5 Torr. CSF PCO2 rapidly equilibrated with the elevated PaCO2. Despite the much lower non-HCO3- buffer capacity in the CSF, CSF pH was not depressed to the same extent as blood pHa. CSF pH was also regulated rapidly, returning to control levels by 8-10 h, whereas pHa remained significantly depressed at 24 h. Similarly, the pHis of the weakly buffered brain and heart ventricle were initially compensated more rapidly than those of more strongly buffered white muscle and red blood cells. However, brain pHi adjustment slowed markedly after 4 h and stabilized at only 70% compensation by 20-24 h, suggesting that brain intracellular acidosis may play a role in the long-term increase in ventilation. CSF and brain were the only compartments which did not exhibit an apparent compounding metabolic acidosis during the initial stage...Continue Reading
References
Extracellular and intracellular pH with changes of temperature in the dogfish Scyliorhinus stellaris
Citations
Capacity for intracellular pH compensation during hypercapnia in white sturgeon primary liver cells.
Effect of hypercapnia on intracellular pH regulation in a rainbow trout hepatoma cell line, RTH 149.
Intracellular acid-base responses to environmental hyperoxia and normoxic recovery in rainbow trout.
Related Concepts
Related Feeds
CSF & Lymphatic System
This feed focuses on Cerebral Spinal Fluid (CSF) and the lymphatic system. Discover the latest papers using imaging techniques to track CSF outflow into the lymphatic system in animal models.