an epithelial channel blocker; also blocks voltage-gated Na+ channels; anti-hypertensive.

Pyrazinoylguanidine‚ C₆H8ClN7O .HCl ‚ synthetic.

potassium-sparing diuretic; ion transporters‚ enzymes and receptors inhibitor.
10-⁶ M reversibly inhibit Na⁺ transport in Na⁺ channels of the high resistance apical plasma epithelial membrane‚ when added to the solution bathing this membrane. Has no effect on Na⁺ transport in basolateral plasma membrane [3-4]. The Na+ channel is the

only ion transporter inhibited by Amiloride with an IC₅₀ of less than 1 µM. IC₅₀ in urinary epithelia = 0.34 µM‚ evaluated by the method of Cuthbert et al. 1978 [1].

it is a weak reversible inhibitor of Na⁺/Ca²⁺ exchanger.

IC₅₀ = 2 mM for Na⁺-coupled solute transport in brush border membrane vesicles from rabbit kidney cortex and in LLC-PK1/CL4 cells [5].

1. Kleyman T.R. et al., "Amiloride and its analogs as tools in the study of ion transport." J. Membr. Biol. (1988). 105:1-21
2. Garritsen A. et al., "Interaction of Amiloride and its analogs with Adenosine A1 receptors in calf bain", Biochem Pharmacol. (1990). 40(4):827
3. Bently P.J., J. Physiol. (London) (1968). 195:317-330
4. Sariban-Sohraby S. et al., Am. J. Physiol. (1986). 250:C175-C190
5. Harris R.C. et al., Kidney Int. (1985). 27:310