Effect of substance P and eledoisin on K efflux, amylase release and cyclic nucleotide levels in slices of rat parotid gland

The undecapeptides, substance P and eledosin, caused a rapid, concentration-dependent increase in K⁺ efflux and amylase release from parotid tissue slices. The effects were not blocked by β-adrenergic, α-adrenergic, or cholinergic anatagonists. Incubation buffer calcium was required for stimulation of K⁺ efflux and amylase release. The action of the undecapeptides was independent of any effects on parotid cyclic AMP or cyclic GMP levels. Since the actions of the undecapeptides were Ca²⁺ dependent and no effects on cyclic nucleotide levels were discerned it was concluded that Ca²⁺ plays a primary role in agonist regulation of K⁺ efflux from the parotid.