抄録
The conception of "electrogenic ion pump", actively separating charges across cell membranes, has been recently developed as a concequence of the recognition of the more intimate relationship between the mechanism generating resting membrane potential and the energy metabolism of the cell than formerly supposed. Existence of the resting potential larger than the equilibrium potential of any major permeable ion across cell membrance supports the above view and is regarded as a safety criterion for electrogenic activity. Another criterion, rapidity of the depolarization caused by the application of inhibitory reagents or conditions for energy metabolism, is examined critically taking several experimental results for instances. The investigations towards the energy sources for electrogenic activity and several hypothetical models for electrogenic ion pump are also reviewed. The ion which is transported across membrane by the electhogenic mechanism seems to be H+ in most plant cells, though in some cases Cl- is a possible candidate. The role of H+ in plant cells as a substitute of Na+ in the case of animal cells is reviewed with special reference to the "co-transport" of organic molecules and also from the view point of origin and evolution of the membrane transport systems.
