Catecholamines in human saliva

Catecholamines are readily detectable in human saliva but their origin is u nclear. Norepinephrine (NE) was stable in saliva stored at 4 degrees for 2 hours but 11 +/- 3% degraded after storage at 25 degrees for 1 hour. We int ravenously infused 3H-NE into humans and measured levels of 3H-NE and its m etabolites in both saliva and forearm venous plasma (a sire whose plasma NE levels reflect both local uptake and release of NE). 3H-NE levels in saliv a continued to rise for 1 hour even though forearm plasma levels had platea ued by 5 min. By 65 min into the infusion the ratio of 3H-NE:nonradioactive NE was similar in saliva and forearm venous plasma. The ratio of NE,epinep hrine (E) was similar in saliva and forearm venous plasma at all time point s. Chewing induced salivation, acid at least tripled the amount of NE, E an d 3H-NE released into saliva per minute, but decreased their concentration in saliva by as much as one half. Saliva NE level was unaltered after 15 mi n of standing but was increased by 31% after 1 hour of upright posture. Our data imply that the NE present in human saliva comes from both the bloodst ream and from salivary sympathetic nerves, The finding that diffusion of bl ood NE into saliva takes roughly 1 hour to complete suggests that NE in sal iva is a poor index of acute changes in sympathetic activity, (C) 2001 Else vier Science Inc. All rights reserved.