Effect of Mercurascan on sodium transport in frog skin and bladder.

The authors studied the effect of Mercurascan (MSC) (a hydroxy- mercury derivative of fluorescein) on electrical parameters, namely potential difference (P.D.) and short circuit current (S.C.C.) of frog skin and on the ability of frog bladder tissue to accumulate sodium ions in experiments in vitro. It was found that MSC, in 10(-4) mol/l concentration, reduced the S.C.C., after a brief initial increase, to 5% of the original value and that the P.D. fell steadily right from the outset. In 10(-5) mol/l concentration it raised the S.C.C. by 60% and the increase lasted several hours. The P.D. was unaffected. In 10(-7) and 10(-6) mol/l concentration MSC had no effect on the NA+ content of a nonpolarized frog bladder tissue preparation, but a 10(-5) nol/l concentration sharply reduced it. The effect of MSC on membrane Na+--K+ ATPase, i.e. on the energy metabolism of cellular tissue, is discussed with reference to these results.