Inhibition of low-density cell formation by bumetanide.

Bumetanide was added from 100-fold stock solutions in DMSO to give final concentrations of 1 mM or 10 μM in buffer A. The same volume of DMSO was added to the control channel. Suspensions were preincubated with mixing for 20 minutes at 22°C before cycling. (A) It was found that 1 mM bumetanide decreased low-density cell formation compared with the concurrent control by 45% during fast oxy/deoxy cycling and by 37% during oxy incubation. (B) The presence of 10 μM bumetanide had no effect on low-density cell formation during oxy/deoxy cycling (P > .4).