Takagi S F, Kitamura H, Imai K, Takeuchi H
J Gen Physiol. 1969 Jan;53(1):115-30. doi: 10.1085/jgp.53.1.115.
In the negative EOG-generating process a cation which can substitute for Na(+) was sought among the monovalent ions, Li(+), Rb(+), Cs(+), NH(4) (+), and TEA(+), the divalent ions, Mg(++), Ca(++), Sr(++), Ba(++), Zn(++), Cd(++), Mn(++), Co(++), and Ni(++), and the trivalent ions, Al(+++) and Fe(+++). In Ringer solutions in which Na(+) was replaced by one of these cations the negative EOG's decreased in amplitude and could not maintain the original amplitudes. In K(+)-Ringer solution in which Na(+) was replaced by K(+), the negative EOG's reversed their polarity. Recovery of these reversed potentials was examined in modified Ringer solutions in which Na(+) was replaced by one of the above cations. Complete recovery was found only in the normal Ringer solution. Thus, it was clarified that Na(+) plays an irreplaceable role in the generation of the negative EOG's. The sieve hypothesis which was valid for the positive EOG-generating membrane or IPSP was not found applicable in any form to the negative EOG-generating membrane. The reversal of the negative EOG's found in K(+)- , Rb(+)- , and Ba(++)-Ringer solutions was attributed to the exit of the internal K(+). It is, however, not known whether or not Cl(-) permeability increases in these Na(+)-free solutions and contributes to the generation of the reversed EOG's.
在负向眼电图产生过程中,在单价离子Li⁺、Rb⁺、Cs⁺、NH₄⁺和TEA⁺、二价离子Mg²⁺、Ca²⁺、Sr²⁺、Ba²⁺、Zn²⁺、Cd²⁺、Mn²⁺、Co²⁺和Ni²⁺以及三价离子Al³⁺和Fe³⁺中寻找可替代Na⁺的阳离子。在将Na⁺替换为这些阳离子之一的林格氏溶液中,负向眼电图的振幅减小,无法维持原始振幅。在将Na⁺替换为K⁺的K⁺-林格氏溶液中,负向眼电图的极性发生反转。在将Na⁺替换为上述阳离子之一的改良林格氏溶液中检查这些反转电位的恢复情况。仅在正常林格氏溶液中发现完全恢复。因此,明确了Na⁺在负向眼电图的产生中起不可替代的作用。对正向眼电图产生膜或抑制性突触后电位有效的筛孔假说未发现以任何形式适用于负向眼电图产生膜。在K⁺-、Rb⁺-和Ba²⁺-林格氏溶液中发现的负向眼电图的反转归因于细胞内K⁺的外流。然而,尚不清楚在这些无Na⁺溶液中Cl⁻通透性是否增加并有助于反转眼电图的产生。