The Secretion of Lithium in Human Mixed Saliva: Effects of Ingested Lithium on Electrolyte Distribution in Saliva and Serum

Abstract

Outlining some of the more salient findings of this investigation: 1. Lithium appears in both saliva and serum without showing any appreciable time transient (found in saliva as early as one hour after administration). 2. Lithium is present in saliva at concentrations approximately two times that found in serum, this ratio holding in different diagnostic categories and over a wide range of dosages. 3. A concentration gradient obtained between saliva-serum lithium suggests an alternative method for determining blood levels. 4. An apparent correspondence exists between elevated concentrations of lithium ion and time of clinical improvement in manic patients. 5. Manic patients showing clinical improvement may be divided into two groups with respect to lithium distribution, one showing decreased lithium levels after the mania breaks and not the other. 6. There is a positive dependency between the concentration of lithium and volume of saliva secretions in function of time. Lithium appears capable of shifting volume dependency from sodium to itself. 7. Chronic lithium administration reduces plasma sodium and increases saliva sodium with concomitant increase of the Na/K ratio of saliva. There is no significant overall alteration of the potassium electrolyte in either saliva or serum. 8. Potassium was found in saliva at levels 2—4 times its concentration in serum, whereas sodium showed serum concentrations 4-5 times that of saliva. These findings which correspond to normal physiological gradients for these ions were generally not significantly altered by the introduction of lithium. Lithium, then, can be said to resemble potassium and differ from sodium in that it concentrates higher in saliva than serum. 9. Sodium tends to follow a reciprocal relationship with lithium. This supports existing beliefs that lithium is capable of replacing sodium in various systems. 10. It has long been recognized that the secretion of sodium and potassium (and chloride) in saliva is the result of osmotic activity by the secreting glands under the control of the adreno-cortical axis. The present findings are discussed in regard to such hormonal influence. 11. It is proposed that human mixed saliva may be used as a meaningful investigational tool in studying the effects of lithium.

Lithium Content, Buffering Capacity and Flow Rate of Saliva and Caries Experience of Australian Children

“…The inverse as sociation demonstrated between the Li content of saliva and flow rate is in ac cordance with the findings of Spring and Spines [1969] for subjects receiving short term Li therapy and with those of Scham schula et al [1978] for untreated subjects. In early studies in dogs [Burgen, 1958], cats [Good, 1903] and in a more recent study of humans [Shopsin et al, 1969], in which large quantities of Li were adminis tered, the corresponding associations were conflicting and inconclusive. We are not aware of previous studies concerned with the relationship between the buffering ca pacity and Li content of saliva.…”

Salivary and urinary lithium clearance while recumbent and upright

“…Lithium excretion in saliva appears to be an active process resembling that of potassium excretion in saliva and is not markedly influenced by dietary regimens. 5 On the other hand, lithium excretion in urine appears to be a passive process resembling that of sodium excretion in the proximal tubule, which is affected by posture-induced changes in glomerular filtration rate but not by urine flow rate and is also influenced by dietary regimens. 7 • 9.…”

Review of Psychotropic Agents Associated with Sialorrhoea, Except Clozapine

“…17 Another report suggested that lithium levels in the serum are directly proportional to the severity of sialorrhoea. 22 Lithium levels affect the catecholamine metabolism in the central nervous system but have no effects on the peripheral nervous system. 22,23,26,27 The secretion of lithium ions in the saliva is known to cause persistent localized irritation.…”