Kinins and epithelial ion transport in the alimentary tract.

Kinin effects on epithelial electrogenic ion transport are reviewed, with reference to the alimentary tract. The transported ion is usually chloride, but some epithelia also transport bicarbonate. The key components of the transport system are the sodium-potassium-chloride cotransporter, Na+-K+ ATPase (both located basolaterally) and the CFTR chloride channel (located apically). Activation of K+-channels in both membranes may secondarily affect the anion transport mechanism. The types of kinin receptors that cause chloride secretion, the second messengers involved and the possible functional responsibilities of the kinin-activated secretory mechanism are discussed.