Figure 4. Two electrode voltage-clamp of Xenopus oocytes.

Inward currents elicited by solutions and NP suspensions in NT (A) and rDMT1 transfected (B–D) representative oocytes. Oocytes were clamped at a holding potential of −40 mV and exposed to MnCl₂ (1) and CoCl₂ (2) solutions, to Co₃O₄ (3) and Co (4) NP suspensions and to their surnatants obtained at time 0 h (a) and 24 h (b). (E): Current mean values (±SE) obtained by subtracting from the current in the presence of the substrate, the current in its absence and normalizing to the Mn²⁺ current, a reference for divalent metal transporters in electrophysiological studies 6 to 12 oocytes from 4 batches.