Lithium-induced alterations in nucleoside triphosphate levels in human brain: a proton-decoupled 31P magnetic resonance spectroscopy study

We examined how lithium's demonstrated effects on various cellular processes in human brain would be reflected in the 31P magnetic resonance spectra of living human beings with respect to brain high-energy phosphate metabolites. Eight healthy volunteers received a baseline 31P magnetic resonance spectroscopy (MRS) scan, after which they received lithium carbonate, 900 mg/day, for 14 days. Follow-up MRS scans were obtained on day 7 and on day 14. We detected a lithium-induced decrease in alpha-, beta-, gamma- and total nucleoside triphosphate NTP levels with chronic administration of lithium. On day 7, significant decreases were noted in gamma-NTP (14%) and total NTP (11%) levels. There was a trend for a decrease in beta-NTP (11%) levels. On day 14, significant decreases were noted in alpha-NTP (7%) and total NTP (8%) levels. There was a trend for a decrease in beta-NTP (16%) levels. Lithium caused a 25% reduction in inorganic phosphate (Pi) levels on day 14. The theoretical relevance of the lithium-induced alterations on brain high-energy phosphates to the lithium-induced modifications of neuroplasticity is discussed.