title: Regulation of intracellular pH in vertebrate central neurons.
abstract: The regulation of intracellular pH (pHi) was investigated in reticulospinal neurons of the lamprey using ion-selective microelectrodes. Steady-state pHi in 23 mM HCO-3-buffered Ringer was 7.44 +/- 0.03 with a membrane potential of 54 +/- 4 mV (mean +/- S.E.M., n = 6). In nominally HCO-3-free solutions, pHi recovery from acid loading was blocked by 10(-3)M amiloride. Recovery was stimulated by transition to HCO-3-containing solutions. Results suggest that pHi regulation in lamprey reticulospinal neurons is mediated by a Na+-H+ exchanger. The presence of a distinct, HCO-3-dependent pHi regulatory mechanism is postulated.
mesh_terms: D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D002463:Cell Membrane Permeability; D005116:Extrapyramidal Tracts / Q000378:metabolism*; D005399:Fishes / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007798:Lampreys / Q000378:metabolism*; D012154:Reticular Formation / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism
chemical_list: D000584:Amiloride; D006859:Hydrogen; D012964:Sodium