S0859 is an N-cyanosulphonamide that blocks the sodium/bicarbonate cotransporter (NBC, also known as SLC4A7), which regulates intracellular pH, particularly in myocytes. It inhibits intracellular pH recovery in myocytes with a Ki value of 1.7 μM, with full inhibition occurring at ~30 μM. S0859 does not affect other exchange proteins or enzymes that might regulate intracellular pH. It prevents changes in pH associated with depolarization and hyperpolarization of ventricular myocytes from rabbit, rat, and guinea pig. S0859 has also been used to study the role of NBC in coronary endothelial cells, cancer cells, embryonic kidney cells, and neutrophils.
