Synergistic Effect of Cyclopropane and Epinephrine on Sodium Transport in Toad Bladder

Abstract

In the short-circuited toad bladder cyclopropane enhanced active Na transport whereas in bladders taken from toads pretreated with reserpine, cyclopropane was an inhibitor of Na transport. Normal toad bladder contained a significant concentration of epinephrine which was reduced in animals pretreated with reserpine. Epinephrine alone stimulated Na transport of the bladder and cyclopropane and epinephrine had a synergistic effect upon the ion transport. The stimulating effect of cyclopropane when used alone could be reversed by an [alpha]-blocker, but not by a [beta]-blocker. When the concentration of [alpha]-blocker was high enough, cyclopropane inhibited Na transport.