Biological activities of cystic fibrosis serum. IV. Stimulation of the calcium mediated K+ efflux from rat submandibular gland fragments.

Cystic fibrosis (CF) and heterozygote sera stimulate a significant K+ efflux from rat submandibular gland fragments in the presence of 1 mM ouabain. This sensitive parameter can be maximally stimulated by as little as 0.5% CF serum and is inhibited by the calcium channel blocker D600 and EGTA.

Agonist-induced secretions and potassium release from rat submandibular gland slices.

Secretory activity induced by stimulation of alpha-adrenergic, beta-adrenergic, and muscarinic cholingeric receptors and by dibutyryl cAMP and 8-bromo cGMP has been investigated in rat submandibular tissue slices. Isoproterenol produced a sialic acid secretion from the acinar cells that was inhibited by propranolol, but not by phenoxybenzamine or atropine. Dibutyryl cAMP produced a sialic acid secretion from the acinar cells that was not inhibited by propranolol, phenoxybenzamine, or atropine.