tokens: After washing and resuspension in RPMI-1640 medium , cells were incubated at 37 degrees C for 1 h with different concentrations of [ 3H ] aldosterone plus a 100-fold concentration of RU-26988 ( 11 alpha , 17 alpha-dihydroxy-17 beta-propynylandrost-1 , 4 , 6-trien-3-one ) , with or without an excess of unlabeled aldosterone .