Kallikrein and salivary secretion in rats during heat exposure

RP 67850, a NK1 receptor antagonist, inhibited the sialogogic effect of Substance P (SP). Heat-induced salivation was indirectly measured through the changes in body weight. Thermolytic salivation was reduced by atropine and RP 67580 and thus would be mainly controlled by acetylcholine and tachykinins. This salivation was associated with a large depletion of kallikrein in submaxillary glands. This depletion was not inhibited by atropine and RP 67580. Feeding has been reported to reduce amylase activity in parotid glands but did not modify the kallikrein content in submaxillary glands. Heat exposure did not modify amylase activity. There is a dissociation between the releases of amylase and kallikrein from salivary glands.