[42] Cation transport probes: The amiloride series

This chapter focuses on the cation transport probes that is it describes the various the amiloride series. Several recent studies have used radiolabeled amiloride analogs to identify and characterize binding sites of amiloride analogs in plasma membranes or microsomal membranes derived from cells known to have amilofide-sensitive transporters. Methods for assaying the binding of amiloride analogs to membranes and to detergent-solubllized proteins are outlined in this chapter. The use of amiloride and its analogs in the study of ion transport requires a knowledge of the pharmacology of inhibition of transport proteins, and of effects on enzymes, receptors, and other cellular processes, such as DNA, RNA, and protein synthesis, and cellular metabolism. This chapter reviews the pharmacology of inhibition of these processes by amiloride an its analogs, as well as the use of amiloride analogs as potential probes for the characterization of ion transport systems.