Secretory potentials, secretory rate and water permeability of the duct system in the cat submandibular gland during perfusion with calcium-free Locke's solution.

It has previously been shown that the cat submandibular gland is unable to secrete in the absence of calcium. As the formation of saliva is the result of transport processes in the acini as well as the duct system, the effect of omitting calcium was investigated in both these parts of the gland. In the acini secretory potentials which are signs of an active ion transport, were recorded, and in the duct system water permeability was measured using tritium labelled water. In spite of severe reduction in the secretory ability of the gland, secretory potentials of normal size could still be evoked in the absence of calcium, but the shape of the potentials was altered. No striking effects on the water permeability of the duct system could be detected.