Ouabain insensitive ATPase in planaria

Abstract 1. 1. Ouabain, up to 8·10 −3 M is virtually non-toxic for planaria ( Dugesia gonocephala ). 2. 2. No behavioural changes are observed during ouabain treatment. 3. 3. Regeneration of sectioned specimens occurs normally in ouabain solutions. 4. 4. Planaria homogenates show a Mg 2+ dependent ATPase, not activated by Na + + K + and ouabain insensitive. 5. 5. K + stimulates, whereas Na + (or Na + + K + ) inhibits Mg 2+ dependent ATPase.