The synergism and antagonism of cations.
The excess of the potassium, magnesium or hydrogen ions, as well as the diminution of the sodium ions concentration in the perfusion fluid can block the electrical and mechanical activities of the isolated heart of frog. These effects can be eliminated by a concomitant increase in the concentration of the calcium, sodium, or hydroxyl ions. The above-mentioned results suggest the existence of two types of ionic constellations, which are antagonistic: one formed from magnesium and potassium ions and functioning in a medium with an acid pH, and another one formed from calcium and sodium ions and functioning in an alkaline medium.
D000818:Animals; D001001:Anura; D002412:Cations; D004336:Drug Antagonism; D004357:Drug Synergism; D006321:Heart / Q000187:drug effects*; D006859:Hydrogen / Q000494:pharmacology*; D008274:Magnesium / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology*; D012964:Sodium / Q000494:pharmacology*
D002412:Cations; D006859:Hydrogen; D012964:Sodium; D008274:Magnesium; D011188:Potassium