A transient release of potassium mediated by the action of substance P on rat parotid slices.

Abstract

Substance P (a peptide of 11 amino acids) caused a Ca-dependent release of K+ from rat parotid slices. The response to substance P differed from the .alpha.-adrenergic and the cholinergic responses in that it was transient to a lesser extent, and was not inhibited by phentolamine and atropine. Substance P caused little, if any, amylase secretion. Successive additions of the peptide to the slice system maintained the effect of K+ release indicating that the transient response to a single addition of the peptide was due to inactivation of substance P and not due to a decline in the tissue response.