The effects of duration and intensity of stimulation on total protein and mucin concentrations in resting and stimulated whole saliva

The present investigation has characterized the influence of the duration a nd intensity of stimulation on the secretion pattern of total protein and s alivary mucins MG1 and MG2 in whole saliva. Resting and stimulated whole sa liva was collected from six healthy subjects on 2 consecutive days. Whole s aliva was collected for 2 five-minute intervals under resting conditions fo llowed by collection under masticatory stimulation induced by the chewing o f parafilm (I g) at 10 or 60 strokes/min for 15 min. Flow rates were differ ent under the 2 levels of stimulation. The concentration of total protein w as different in resting and stimulated whole saliva but was not affected by the duration or intensity of stimulation. Analysis of mucin concentrations determined by capture ELISAs revealed that the pattern of MG1 secretion wa s similar to that of total protein. The pattern of MG2 secretion was unique in that no differences were observed in the concentration of this mucin un der resting and stimulated conditions. This study shows that the pattern of protein secretion in whole saliva does not reflect the combined pattern ob served for protein secretion in parotid and submandibular/sublingual glands , and that the secretion patterns of MG I and MG2 in whole saliva are quite different from one another.