THE INFLUENCE OF SENSORY STIMULATION (ACUPUNCTURE) ON THE RELEASE OF NEUROPEPTIDES IN THE SALIVA OF HEALTHY-SUBJECTS

In recent studies we have shown that xerostomia (dry mouth) can be tre ated successfully with sensory stimulation (acupuncture). The increase of saliva secretion lasted often for at least one year. Some neuropep tides have been found to influence the secretion of saliva. The aim of this study was to investigate the mechanisms behind the effect of acu puncture on salivary secretion by measuring the release of neuropeptid es in saliva under the influence of sensory stimulation. VIP-like immu noreactivity (VIP-LI), NPY-LI, SP-LI, CGRP-LI and NKA-LI were analysed in the saliva of eight healthy subjects. Manual acupuncture and acupu ncture with low-frequency electrical stimulation (2 Hz) were used. The saliva was collected during 20 minutes before the start of acupunctur e stimulation, then during 20 minutes while the needles were in situ a nd then for another 20 minutes after the needles were removed. Four di fferent saliva sampling techniques were used: whole resting saliva, wh ole saliva stimulated by paraffin-chewing, whole saliva stimulated by citric acid (1%), and parotid saliva, also stimulated with citric acid (1%). The results showed significant increases in the release of CGRP , NPY and VIP both during and after acupuncture stimulation, especiall y in connection with electro-acupuncture. SP showed only few increases , mainly in connection with electro-acupuncture, whereas NKA generally was unaffected by the acupuncture stimulation. The sensory stimulatio n-induced increase in the release of CGRP, NPY and VIP in the saliva c ould be an indication of their role in the improvement of salivary flo w rates in xerostomic patients who had been treated with acupuncture.