Effect of loop diuretics on cholinergic neurotransmission in human airways in vitro.

Abstract

In human airways in vitro both frusemide and bumetanide produced a concentration-dependent inhibition of the EFS-induced cholinergic contraction. This inhibition is mediated through a prejunctional mechanism. Epithelium removal was necessary to achieve this effect. The mechanism of action of frusemide and bumetanide on airway nerves remains unclear: inhibition of the Na-K-Cl cotransporter is a possibility and, for frusemide, release of endogenous cyclooxygenase products may be involved. Carbonic anhydrase inhibition, on the other hand, is unlikely to be a factor.