Abstract
Repeated administrations of lithium salts (Li2CO3 or LiCl, 60 and 85 mg/kg, respectively, twice a day for five days) to rats increased brain 5-hydroxyindoleacetic acid (5-HIAA) by about 80% and brain serotonin by 15 to 20%. The changes were not due to an inhibition of 5-HIAA transport from brain, but to an increase in the rate of synthesis of brain serotonin. Rate of serotonin synthesis was measured by multiplying the rate constant of 5-HIAA decline, after inhibition of monoamine oxidase, by the steady-state level of 5-HIAA. The calculation indicated that lithium increased the synthesis rate of brain serotonin by about 80%. Moreover, chronic treatment with lithium salts also increased the levels of brain tryptophan by about 70%, suggesting that this could be the mechanism by which lithium stimulates serotonin synthesis.
Footnotes
- Received July 23, 1970.
- Accepted April 4, 1971.
- © 1971 by The Williams & Wilkins Co.
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|