Neurochemical Research

, Volume 31, Issue 6, pp 759–765 | Cite as

Measuring Brain Uptake and Incorporation into Brain Phosphatidylinositol of Plasma myo-[2H6]Inositol in Unanesthetized Rats: An Approach to Estimate In vivo Brain Phosphatidylinositol Turnover

  • Kaizong Ma
  • Joseph Deutsch
  • Nelly E. Villacreses
  • Thad A. Rosenberger
  • Stanley I. Rapoport
  • H. Umesha Shetty
Original Paper

Abstract

The in vivo rate of turnover of phosphatidylinositol (PtdIns) in brain is not known. In brain, certain receptor-mediated signal transduction involves metabolism of PtdIns and a method to measure its turnover in awake animals is useful in studying the effect of lithium and other therapeutic agents. In a method described here, rats were infused subcutaneously with myo-[2H6]inositol (Ins*) using an osmotic pump and, at 1 and 8 weeks, concentrations of free myo-inositol (Ins) and Ins* in plasma and brain were measured by GC-MS (chemical ionization). Also, PtdIns and PtdIns* together in brain were isolated, and Ins and Ins* from their headgroups were released enzymatically and specific activity of incorporated inositol was measured. The specific activity of inositol reached a steady state in plasma within 1 week of infusion, but not in brain even at 8 weeks. However, in brain, the specific activity of phosphatidylinositol was same as that of inositol at both time-points, suggestive of fast turnover of PtdIns. The animal experiment and the analytical methodology described here should be useful for measuring the rate of turnover of brain PtdIns in pathological and drug treatment conditions.

Keywords

myo-Inositol Phosphatidylinositol turnover Brain uptake GC-MS Stable isotope Osmotic pump Na+/myo-inositol cotransporter 

References

  1. 1.
    Berridge MJ (1993) Inositol trisphosphate and calcium signaling. Nature 361:315–325PubMedCrossRefGoogle Scholar
  2. 2.
    Fruman DA, Meyers RE, Cantley LC (1998) Phosphoinositide kinases. Annu Rev Biochem 67:481–507PubMedCrossRefGoogle Scholar
  3. 3.
    Greene DA, De Jesus PV Jr, Winegrad AI (1975) Effects of insulin and dietary myoinositol on impaired peripheral motor nerve conduction velocity in acute streptozotocin diabetes. J Clin Invest 55:1326–1336PubMedCrossRefGoogle Scholar
  4. 4.
    Zhu X, Eichberg J (1990) A myo-inositol pool utilized for phosphatidylinositol synthesis is depleted in sciatic nerve from rats with streptozotocin-induced diabetes. Proc Natl Acad Sci USA 87:9818–9822PubMedCrossRefGoogle Scholar
  5. 5.
    Shetty HU, Schapiro MB, Holloway HW, Rapoport SI (1995) Polyol profiles in Down syndrome: myo-inositol, specifically, is elevated in the cerebrospinal fluid. J Clin Invest 95:542–546PubMedCrossRefGoogle Scholar
  6. 6.
    Huang W, Alexander GE, Daly EM, Shetty HU, Krasuski JS, Rapoport SI, Schapiro MB (1999) High brain myo-inositol levels in the predementia phase of Alzheimer’s disease in adults with Down’s syndrome: a 1H MRS study. Am J Psychiatry 156:1879–1886PubMedGoogle Scholar
  7. 7.
    Ito E, Oka K, Etcheberrigaray R, Nelson TJ, McPhie DL, Tofel-Grehl B, Gibson GE, Alkon DL (1994) Internal Ca2+ mobilization is altered in fibroblasts from patients with Alzheimer disease. Proc Natl Acad Sci USA 91:534–538PubMedCrossRefGoogle Scholar
  8. 8.
    Shonk TK, Moats RA, Gifford P, Michaelis T, Mandigo JC, Izumi J, Ross BD (1995) Probable Alzheimer disease: diagnosis with proton MR spectroscopy. Radiology 195:65–72PubMedGoogle Scholar
  9. 9.
    Davanzo P, Yue K, Thomas MA, Belin T, Mintz J, Venkatraman TN, Santoro E, Barnett S, McCracken J (2003) Proton magnetic resonance spectroscopy of bipolar disorder versus intermittent explosive disorder in children and adolescents. Am J Psychiatry 160:1442–1452PubMedCrossRefGoogle Scholar
  10. 10.
    Shimon H, Agam G, Belmaker RH, Hyde TM, Kleinman JE (1997) Reduced frontal cortex inositol levels in postmortem brain of suicide victims and patients with bipolar disorder. Am J Psychiatry 154:1148–1150PubMedGoogle Scholar
  11. 11.
    Hallcher LM, Sherman WR (1980) The effects of lithium ion and other agents on the activity of myo-inositol−1-phosphatase from bovine brain. J Biol Chem 255:10,896–10,901Google Scholar
  12. 12.
    Moore GJ, Bebchuk JM, Parrish JK, Faulk MW, Arfken CL, Strahl-Bevaaqua J, Manji HK (1999) Temporal dissociation between lithium-induced changes in frontal lobe myo-inositol and clinical response in manic-depressive illness. Am J Psychiatry 156:1902–1908PubMedGoogle Scholar
  13. 13.
    Berridge MJ, Downes CP, Hanley MR (1989) Neural and developmental actions of lithium: a unifying hypothesis. Cell 59:411–419PubMedCrossRefGoogle Scholar
  14. 14.
    Harwood AJ (2005) Lithium and bipolar mood disorder: the inositol-depletion hypothesis revisited. Mol Psychiatry 10:117–126PubMedCrossRefGoogle Scholar
  15. 15.
    Robinson PJ, Noronha J, DeGeorge JJ, Freed LM, Nariai T, Rapoport SI (1992) A quantitative method for measuring regional in vivo fatty-acid incorporation into and turnover within brain phospholipids: review and critical analysis. Brain Res Rev 17:187–214CrossRefPubMedGoogle Scholar
  16. 16.
    Chikhale EG, Balbo A, Galdzicki Z, Rapoport SI, Shetty HU (2001) Measurement of myo-inositol turnover in phosphatidylinositol: description of a model and mass spectrometric method for cultured cortical neurons. Biochemistry 40:11,114–11,120CrossRefGoogle Scholar
  17. 17.
    Finegold D, Lattimer SA, Nolle S, Bernstein M, Greene DA (1983) Polyol pathway activity and myo-inositol metabolism: a suggested relationship in the pathogenesis of diabetic neuropathy. Diabetes 32:988–992PubMedCrossRefGoogle Scholar
  18. 18.
    Moats RA, Lien Y-HH, Filippi D, Ross BD (1993) Decrease in cerebral inositols in rats and humans. Biochem J 295:15–18PubMedGoogle Scholar
  19. 19.
    Huang W, Alexander GE, Chang L, Shetty HU, Krasuski JS, Rapoport SI, Schapiro MB (2001) Brain metabolite concentration and dementia severity in Alzheimer’s disease: a 1H MRS study. Neurology 57:626–632PubMedGoogle Scholar
  20. 20.
    Shetty HU, Holloway HW, Rapoport SI (1995) Capillary gas chromatography combined with ion trap detection for quantitative profiling of polyols in cerebrospinal fluid and plasma. Anal Biochem 224:279–285PubMedCrossRefGoogle Scholar
  21. 21.
    Rouser G, Fleischer S, Yamamoto A (1970) Two dimensional thin layer chromatographic separation of polar lipids and determination of phospholipids by phosphorus analysis of spots. Lipids 5:494–496PubMedCrossRefGoogle Scholar
  22. 22.
    Stokes CE, Hawthorne JN (1987) Reduced phosphoinositide concentrations in anterior temporal cortex of Alzheimer-diseased brains. J Neurochem 48:1018–1021PubMedCrossRefGoogle Scholar
  23. 23.
    Cooper J, Bloom FE, Roth RH (eds) (2003) The biochemical basis of neuropharmacology, 2nd edn. Oxford University Press, Oxford, p 404Google Scholar
  24. 24.
    Kwon HM, Yamauchi A, Uchida S, Preston AS, Garcia-Perez A, Burg MB, Handler JS (1992) Cloning of the cDNA for a Na+/myo-inositol cotransporter, a hypertonicity stress protein. J Biol Chem 267:6297–6301PubMedGoogle Scholar
  25. 25.
    Minami Y, Inoue K, Shimada S, Morimura H, Miyai A, Yamauchi A, Matsunaga T, Tohyama M (1996) Rapid and transient up-regulation of Na+/myo-inositol cotransporter transcription in the brain of acute hypernatremic rats. Mol Brain Res 40:64–70CrossRefPubMedGoogle Scholar
  26. 26.
    Soupart A, Silver S, Schroëder B, Sterns R, Decaux G (2002) Rapid (24-hour) reaccumulation of brain organic osmolytes (particularly myo-inositol) in azotemic rats after correction of chronic hyponatremia. J Am Soc Nephrol 13:1433–1441PubMedCrossRefGoogle Scholar
  27. 27.
    Wong YH, Kalmbach SJ, Hartman BK, Sherman WR (1987) Immunochemical staining and enzyme activity measurements show myo-inositol-1-phosphate synthase to be localized in the vasculature of brain. J Neurochem 48:1434–1442PubMedCrossRefGoogle Scholar
  28. 28.
    Weise TJ, Dunlap JA, Conner CE, Grzybowski JA, Lowe WL Jr, Yorek MA (1996) Osmotic regulation of Na-myo-inositol cotransporter mRNA level and activity in endothelial and neural cells. Am J Physiol 270:C990–C997Google Scholar
  29. 29.
    Strange K, Emma F, Paredes A, Morrison R (1994) Osmoregulatory changes in myo-inositol content and Na+/myo-inositol cotransport in rat cortical astrocytes. Glia 12:35–43PubMedCrossRefGoogle Scholar
  30. 30.
    Acevedo LD, Holloway HW, Rapoport SI, Shetty HU (1997) Application of stable isotope tracer combined with mass spectrometric detection for studying myo-inositol uptake by cultured neurons from fetal mouse: effect of trisomy 16. J Mass Spectrom 32:395–400PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Kaizong Ma
    • 1
  • Joseph Deutsch
    • 1
  • Nelly E. Villacreses
    • 1
  • Thad A. Rosenberger
    • 1
  • Stanley I. Rapoport
    • 1
  • H. Umesha Shetty
    • 1
    • 2
  1. 1.Brain Physiology and Metabolism Section, National Institute on AgingNational Institutes of HealthBethesdaUSA
  2. 2.Molecular Imaging Branch, National Institute of Mental HealthNational Institutes of HealthBethesdaUSA

Personalised recommendations