Figure/Graphic 2: Leitfähigkeit - Magnesium
Results from own voltage-clamp experiment using isolated cardiac sheep Purkinje strands, where the slope conductance increases when extra-cellular Mg (Mgo) is reduced. The isochronal current-voltage relationship under control conditions (filled triangles) changes after reducing Mgo to near zero (open triangles) and the outward current increases at depolarised potentials. The presence of 0.3 mM barium decreases the slope conductance to the same values regardless of the presence (closed squares) and absence of Mgo (open squares). Inset: open circles: Bao-sensitivity of currentvoltage relationship in the absence of Mgo, ie, the difference between Mgo sensitive current and Barium-inhibited current-voltage relationship at near 0 Mgo; filled circles: Mgo-sensitive current-voltage relationship, ie, difference between control and the current-voltage relationship at Mgo near 0 mM. It can be seen clearly that changing concentrations of extracellular divalent cation concentrations affect transmembrane conductance through voltage gated ion channels.