NEUROPEPTIDES OF THE AUTONOMIC NERVOUS-SYSTEM IN SJOGRENS-SYNDROME

Objective-To assess the activity level of the autonomic nervous system in Sjogren's syndrome (SS) and to correlate this with stress. Methods -Patients with SS (n=12) and healthy controls (n=10) were analysed for the content of vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY) in their stimulated saliva by radioimmunoassays and for stress by the use of a modified Jenkins Activity Survey (JAS). Results-The da ta are expressed as median (interquartile range). Salivary VIP output (pg/min) and NPY output (pg/min) were high in SS compared with healthy controls (30.0 (15.6, 36.6) versus 12.3 (9.2, 24.0), p=0.045, 4.8 (0. 6, 24.1) versus 0.7 (0.0, 2.4), p=0.038, respectively). Patients exper ienced only a little, but not significantly, more stress than the heal thy controls (stress index -2.8 (-7.7, 6.9) versus -5.2 (-12.9, 2.7), p>0.05). Stress in general was associated with high salivary VIP conce ntrations (r=0.41, p=0.05). Conclusions-These findings show that adequ ately processed saliva (containing aprotinin and EDTA as neuropeptidas e inhibitors) contains measurable amounts of marker peptides of the au tonomic nervous system. Secondly, VIP concentration but not output may be affected by stress, which may act by decreasing watery salivary fl ow. In patients with SS, VIP and NPY outputs are increased. This may i ndicate increased leakage into saliva or efforts to compensate for the diminished salivary flow, or both.