Loop diuretics bind to distinct receptors in renal medulla and cortex.

Receptors which bind [3H]-piretanide were demonstrated on membranes prepared from renal medulla and cortex. They exhibit all the characteristics of a specific receptor such as high affinity, specificity, tissue selectivity, reversible binding kinetics and proportionality between affinity and diuretic effect. Medullary and cortical receptors are clearly distinct since they have different ion requirements.