|
|
||||||||
1. Ion-sensitive glass micro-electrodes were used to measure the intracellular pH (pHi) and the intracellular sodium ion concentration, [Na+]i, in identified Helix aspersa neurones. 2. The injection of small volumes of 0-1 McaCl2, which increased the membrane potential by 10-15 mV for 1-2 min, had little or no effect on [Na+]i. Increases of up to 1 mM in [Na+]i could be reversibly induced by larger injections. 3. Calcium injection caused an immediate decrease in pHi, which appeared to be directly proportional to the amount of calcium injected. Injections causing hyperpolarizations of 10-20 mV which recovered in 2-5 min caused pHi decreases of 0-04-0-15 units. After each of these injections both pHi and the membrane potential recovered exponentially but with different time constants. 4. The injection of calcium at a low rate could decrease pHi without affecting the membrane potential. 5. Neither membrane potential nor pHi were affected by the injection of small volumes of 0-1 M-MgCl2, Injection of CoCl2 produced a large transient decrease in pHi but no significant change in membrane potential. 6. Exposure of the cell to saline equilibrated with 2-5% CO2 greatly reduced the pHi decrease caused by calcium injection but had only small effects on the membrane potential response. 7. It is concluded that most of the injected calcium is exchanged for protons inside the cell.
This article has been cited by other articles:
![]() |
M. CHESLER Regulation and Modulation of pH in the Brain Physiol Rev, October 1, 2003; 83(4): 1183 - 1221. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z.-Q. Xiong, P. Saggau, and J. L. Stringer Activity-Dependent Intracellular Acidification Correlates with the Duration of Seizure Activity J. Neurosci., February 15, 2000; 20(4): 1290 - 1296. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Kiss and S. J. Korn Modulation of N-Type Ca2+ Channels by Intracellular pH in Chick Sensory Neurons J Neurophysiol, April 1, 1999; 81(4): 1839 - 1847. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Tretter, C. Chinopoulos, and V. Adam-Vizi Plasma Membrane Depolarization and Disturbed Na+ Homeostasis Induced by the Protonophore Carbonyl Cyanide-p-trifluoromethoxyphenyl-hydrazon in Isolated Nerve Terminals Mol. Pharmacol., April 1, 1998; 53(4): 734 - 741. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |