title: THE EFFECTS OF VARIOUS IONS ON RESTING AND SPIKE POTENTIALS OF BARNACLE MUSCLE FIBERS.
abstract: Effects of monovalent cations and some anions on the electrical properties of the barnacle muscle fiber membrane were studied when the intra- or extracellular concentrations of those ions were altered by longitudinal intra-cellular injection. The resting potential of the normal fiber decreases linearly with increase of logarithm of [K(+)](out) and the decrement for a tenfold increase in [K(+)](out) is 58 mv when the product, [K(+)](out) .[Cl(-)](out), is kept constant. It also decreases with decreasing [K(+)](in) but is always less than expected theoretically. The deviation becomes larger as [K(+)](in) increases and the resting potential finally starts to decrease with increasing [K(+)](in) for [K(+)](in) > 250 mM. When the internal K(+) concentration is decreased the overshoot of the spike potential increases and the time course of the spike potential becomes more prolonged. In substituting for the internal K(+), Na(+) and sucrose affect the resting and spike potentials similarly. Some organic cations (guanidine, choline, tris, and TMA) behave like sucrose while some other organic cations (TEA, TPA, and TBA) have a specific effect and prolong the spike potential if they are applied intracellularly or extracellularly. In all cases the active membrane potential increases linearly with the logarithm of [Ca(++)](out)/[K(+)](in) and the increment is about 29 mv for tenfold increase in this ratio. The fiber membrane is permeable to Cl(-) and other smaller anions (Br(-) and I(-)) but not to acetate(-) and larger anions (citrate(-), sulfate(-), and methanesulfonate(-)).
mesh_terms: D000085:Acetates; D000200:Action Potentials; D064751:Ammonium Compounds; D000818:Animals; D000838:Anions; D001965:Bromides; D002118:Calcium; D002414:Cations, Monovalent; D002586:Cesium; D002712:Chlorides; D002794:Choline; D002951:Citrates; D003445:Crustacea; D004492:Edetic Acid; D004594:Electrophysiology; D006146:Guanidines; D007454:Iodides; D007477:Ions; D008564:Membrane Potentials; D009132:Muscles; D010600:Pharmacology; D011188:Potassium; D000644:Quaternary Ammonium Compounds; D012106:Research; D012413:Rubidium; D012964:Sodium; D013431:Sulfates; D001468:Thoracica; D014325:Tromethamine
chemical_list: D000085:Acetates; D064751:Ammonium Compounds; D000838:Anions; D001965:Bromides; D002414:Cations, Monovalent; D002712:Chlorides; D002951:Citrates; D006146:Guanidines; D007454:Iodides; D007477:Ions; D000644:Quaternary Ammonium Compounds; D013431:Sulfates; D014325:Tromethamine; D002586:Cesium; D004492:Edetic Acid; D012964:Sodium; D012413:Rubidium; D002794:Choline; D011188:Potassium; D002118:Calcium
keywords: ACETATES; AMMONIUM COMPOUNDS; BROMIDES; CESIUM; CHLORIDES; CHOLINE; CITRATES; CRUSTACEA; EDTA; ELECTROPHYSIOLOGY; EXPERIMENTAL LAB STUDY; GUANIDINES; IODIDES; MUSCLES; PHARMACOLOGY; POTASSIUM; RUBIDIUM; SODIUM; SULFATES; TROMETHAMINE