1984 年 30 巻 8 号 p. 1087-1098
In the present study, inorganic pyrophosphate (PPi), Mg, alkaline-phosphate activity (Al-pase), Ca, Pi and total protein in submandibular and parotid saliva were measured in 19 sialolithiasis and 61 age-matched control subjects in order to understand the possilbe etiologic factor (s) or disposition of this disease. The results can be summarized as follows:
1. Saliva constituents in control subjects
1) The concentrations of PPi and Mg, which are known to be potent inhibitors of calcium phosphate crystal formation, were significantly low in the submandibular gland as compared to those in the parotid. Since available clinical and statistical data on this kind of investigation so far performed show that sialolithiasis occurs most commonly in the submandibular gland, the lower inhibitory activity in this gland might be responsible for the formation of calculus.
2) The concentrations of PPi, Ca and Pi in the submandibular saliva increased with age, while no distinct relationship was demonstrated between the concentrations of PPi, Ca and Pi and age. This finding seems not coincident with the clinical observation that sialolitiasis occurs most frequently in the second, third and fourth decades of life.
3) As for saliva constituents, no significant difference was observed between males and females. This finding well coincided with the clinical observation that no sex difference exists in the incidence of sialolithiasis.
2. Saliva constituents in patients with sialolithiasis
1) With regards to all parameters examined, there was no significant difference between saliva constituents from non-diseased submandibular glands of sialolithiatic patients and those from normal subjects. This suggests that the submandibular gland in the non-diseased side functions normally even in patients with sialolithiasis.
2) The diseased submandibular glands had significantly lower concentrations of Mg and Ca as compared to normal glands, which may indicate that some local disturbancees occur in the diseased submandibular glands from patients with sialolithiasis.
3) The Al-pase activity in the diseased submandibular saliva from patients with sialolithiasis was considerably higher than non-diseased submandibular saliva from sialolithiasis and control subjects, In addition, the concentration of PPi showed a negative correlation to the Al-pase activity (r=0.822, P<0.05). It is assumed tha PPi may rapidly decomposed by high Al-pase activity, ultimately leading to crystal formation together with low Mg levels in the affected submandibular glands.