Effect of Pilocarpine on Levels of Substance P and α-Calcitonin Gene-related Peptide in Human Saliva

Abstract

The effects of pilocarpine on salivary secretion, and substance P immunoreactive substance (SP-IS) and α-calcitonin gene-related peptide immunoreactive substance (α-CGRP-IS) levels in human saliva were studied. After a single oral administration of 5 mg pilocarpine, or placebo (lactose), the peptide levels in saliva were measured using a sensitive enzyme immunoassay. Pilocarpine caused a significant increase in saliva SP-IS levels over the range 2.6±0.3 to 7.8±2.6 pg mL−1, 20–180 min after administration, compared with the placebo group. α-CGRP-IS also increased over the range of 14.9±2.7 to 19.2±3.4 pg mL−1, 40–120 min after administration. Pilocarpine significantly raised the saliva volume 20–120 min after administration and significantly increased the total area under the saliva peptide concentration-time curve of SP-IS (1028.3±386.9 min pg mL−1) and α-CGRP-IS (3401.7±852.4 min pg mL−1) compared with the placebo group (348.2±39.2 and 2508.7±106.6 min pg mL−1, respectively). Pilocarpine may have local effects on SP- and α-CGRP-nerves in salivary glands, and the elevated SP and α-CGRP may stimulate the production of saliva.