H. Mörnstad

Saliva Secretion Rate and Saliva Composition as a Model to Determine the Effect of Antidepressant Drugs on Cholinergic and Noradrenergic Transmission

Three principally different antidepressant drugs--amitriptyline (with effects on both noradrenaline and serotonin reuptake), maprotiline (a selective inhibitor of reuptake of noradrenaline) and zimelidine (a selective inhibitor of reuptake of serotonin) were tested after a single dose and, as concerns maprotiline and zimelidine, after long-term use in healthy volunteers as regards the effects on saliva secretion rate and saliva composition. Amitriptyline gave a strong decrease in both unstimulated and stimulated saliva secretion rate, indicating a strong anticholinergic effect, and a strong increase in the activity of amylase and the content of protein, fucose and hexose in saliva, indicating a strong agonistic effect on noradrenaline transmission. Maprotiline gave an intermediate decrease in saliva secretion rate, and the effect remained after 14 days of treatment. Single doses gave increases in saliva amylase activity and protein content. After 14 days this effect was increased, and there was also a pronounced increase in fucose and hexose content indicating a strong agonistic effect on noradrenaline transmission. Zimelidine gave a low decrease in saliva secretion rate, indicating a mild anticholinergic effect. No certain effect on the saliva composition could be settled after a single dose, but after 14 days there were consistent increases in amylase activity and protein, fucose and hexose content, indicating a facilitation of noradrenaline transmission. Zimelidine as well as its active metabolite, norzimelidine, are selective inhibitors of serotonin reuptake. The action of zimelidine is discussed in view of recent hypotheses about a modulating serotoninergic influence on the noradrenergic system.

Acute Effects of Some Different Antidepressant Drugs on Saliva Composition

In a double-blind controlled cross-over trial on 20 healthy volunteers, the acute effects of single doses of amitriptyline (75 mg), zimelidine (100 mg), maprotiline (75 mg), and placebo were tested on saliva composition. From the current knowledge of the physiological regulation of the salivary glands and the different specificities of the three drugs, different responses from the salivary glands could be expected. As all three drugs have anticholinergic effects that influence the saliva secretion, the concentrations of secreted saliva components had to be recalculated with regard to changes in secretion rate. No changes in saliva composition were recorded after the intake of placebo. The most pronounced changes were observed after amitriptyline intake. Amitriptyline caused increases in the concentrations of proteins, glycoproteins, calcium and potassium. Zimelidine initially decreased the concentrations of glycoproteins and increased the concentration of calcium. Maprotiline increased the concentrations of proteins and sodium. Most of the results fit in well with the theories about facilitated serotoninergic and adrenergic transmission during treatment with antidepressants.

Saliva secretion rate and saliva composition in relation to extraversion

Abstract In this study of 20 healthy volunteers, relationships were sought between degree of extraversion (as determined by means of the EPI) and saliva secretion rate and composition. A significant negative correlation was found between both unstimulated and stimulated saliva secretion rates and extraversion. The correlation was most pronounced in the morning. In the morning introverts had significantly higher unstimulated secretion rates than extraverts. The differences were less pronounced in the afternoon. Introverts had higher concentrations of proteins and glycoproteins in their saliva than had extraverts. The results seem to support theories about a higher cortical arousal and a higher sympathetic activity in introverts than in extraverts.

The risk of dental caries in extraverts

Abstract It has been demonstrated that extraverts have a lower saliva secretion rate than introverts. Furthermore, extraverts as well as subjects with high P-scores on the EPQ have been demonstrated to have a more pronounced risk-taking behaviour, possibly including a tendency to neglect health care programs. Thus it was hypothesised that extraverts and possibly also subjects with high P-scores would have an increased risk of caries. The Swedish translation of the 97 items JEPQ was administered to 101 15-year-old adolescents controlled at the annual dental status health control. Extraverts were found to have significantly more earlier caries and significantly more total caries and a tendency towards higher values in initial and manifest caries. Subjects with high P-scores were found to have significantly more manifest caries. No significant relationships were found between the frequency of caries and the N- or L-scales in the JEPQ.