Changes of intracellular sodium and potassium ion concentrations in isolated rat superior cervical ganglia induced by depolarizing agents.
1. Na and K contents of isolated rat superior cervical ganglia were measured by flame photometry, and intracellular Na and K concentrations ([Na](i) and [K](i)) calculated using Li and (35)SO(4) to determine extracellular space (e.c.s.).2. Resting concentrations after 1-2 hr incubation at 25 degrees C in normal Krebs solution were: [Na](i), 19.8 +/- 0.9 m-mole (kg cell water)(-1); [K](i), 192.7 +/- 2.8 m-mole (kg cell water)(-1) (mean +/- S.E. of mean of thirty-five ganglia). Correction for losses during e.c.s. measurement gave 22 mM [Na](i) and 207 mM [K](i) as probable fresh concentrations.3. Carbachol (180 muM for 4 min) increased [Na](i) by 47.8 +/- 2.9 m-mole (kg cell water)(-1) and decreased [K](i) by 54.6 +/- 4.3 m-mole (kg cell water)(-1). Maximal exchange with carbachol or nicotine (at approximately 1 mM for 4 min) amounted to 80-100 m-mole (kg cell water)(-1). On washing with Krebs solution containing 2.5 mM hexamethonium recovery of ionic concentrations occurred with a rate constant of 0.3-0.4 min(-1).4. Restitution of ganglionic Na and K after carbachol was inhibited by washing with K-free solution, and slowed by ouabain (0.14 mM), cyanide (2 mM) or cooling (Q(10) 2.7 between 17 and 27 degrees C).5. Equilibrium potentials for Na and K (E(Na), E(K)) at rest were calculated to be +49 and -88 mV. At a membrane potential (E(m)) of -70 mV, the permeability ratio P(Na):P(K) was calculated at 0.04:1 (assuming P(Cl):P(K) < 0.1).
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002217:Carbachol / Q000494:pharmacology*; D002463:Cell Membrane Permeability; D003486:Cyanides / Q000494:pharmacology; D005725:Ganglia, Autonomic / Q000187:drug effects / Q000378:metabolism*; D006584:Hexamethonium Compounds / Q000494:pharmacology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009538:Nicotine / Q000494:pharmacology*; D010042:Ouabain / Q000494:pharmacology; D010783:Photometry; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D012964:Sodium / Q000378:metabolism*; D013462:Sulfur Radioisotopes; D013696:Temperature; D013997:Time Factors; D014630:Vagus Nerve
D003486:Cyanides; D006584:Hexamethonium Compounds; D013462:Sulfur Radioisotopes; D010042:Ouabain; D009538:Nicotine; D002217:Carbachol; D012964:Sodium; D011188:Potassium