Neurochemical Research

, Volume 13, Issue 3, pp 213–219 | Cite as

Biotin transport and metabolism in the central nervous system

  • Reynold Spector
  • DOnald M. Mock
Original Articles


The mechanisms by which biotin enters and leaves brain, choroid plexus and cerebrospinal fluid (CSF) were investigated by injecting [3H]biotin either intravenously or intraventricularly into adult rabbits. [3H]biotin, either alone or together with unlabeled biotin was infused at a constant rate into conscious rabbits. At 180 minutes, [3H]biotin had entered CSF, choroid plexus, and brain. In brain, CSF, and plasma, greater than 90% of the nonvolatile3H was associated with [3H]biotin. The addition of 400 μmol/kg unlabeled biotin to the infusion syringe decreased the penetration of [3H]biotin into brain and CSF by approximately 70 percent. Two hours after an intraventricular injection, [3H]biotin was cleared from the CSF more rapidly than mannitol and minimal metabolism of the [3H]biotin had occurred in brain. However, 18 hours after an intraventricular injection, approximately 35% of the [3H]biotin remaining in brain had been covalently incorporated into proteins, presumably into carboxylase apoenzymes. These results show that biotin enters CSF and brain by saturable transport systems that do not depend on metabolism of the biotin. However, [3H]biotin is very slowly incorporated covalently into proteins in brain in vivo.

Key Words

Brain cerebrospinal fluid blood-brain barrier 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Murthy, P. N. A., and Mistry, S. P. 1977. Biotin. Prog. Food Nutr. Sci. 2:405–455.Google Scholar
  2. 2.
    Lee, H-M., Wright, L. D., and McCormick, D. B. 1972. Metabolism of carbonyl-labeled14C-biotin in the rat. J. Nutr. 102:1453–1464.Google Scholar
  3. 3.
    Sander, J. E., Packman, S., and Townsend, J. J. 1982. Brain pyruvate carboxylase and the pathophysiology of biotin-dependent diseases. Neurology 32:878–880.Google Scholar
  4. 4.
    Suchy, S. F., McVoy, J. S., and Wolf, B. 1985. Neurologic symptoms of biotinidase deficiency: Possible explanation. Neurology 35:1510–1511.Google Scholar
  5. 5.
    Spector, R., and Mock, D. M. 1987. Biotin transport through the blood-brain barrier. J. Neurochem. 48:400–404.Google Scholar
  6. 6.
    Takasato, Y., Momma, S., and Smith, Q. R. 1986. Kinetic analysis of cerebrovascular isoleucine transport from saline and plasma. J. Neurochem. 45:1013–1020.Google Scholar
  7. 7.
    Takasato, Y., Rapoport, S. I., and Smith, Q. R. 1984. An in situ brain perfusion technique to study cerebrovascular transport in the rat. Am. J. Physiol. 247:H484-H493.Google Scholar
  8. 8.
    Bhagavan, H. N., and Coursin, D. B. 1970. Depletion of biotin from brain and liver in biotin deficiency. J. Neurochem. 17:289–290.Google Scholar
  9. 9.
    Chastain, J. L., Bowers-Komro, D. M., and McCormick, D. B. 1985. High-performance liquid chromatography of biotin and analogues. J. Chromatogr. 330:153–158.Google Scholar
  10. 10.
    Mock, D. M., and DuBois, D. B. 1986. A sequential, solid-phase assay for biotin in physiologic fluids that correlates with expected biotin status. Anal. Biochem. 153:272–278.Google Scholar
  11. 11.
    Spector, R. 1980. Thymidinee transport in the central nervous system. J. Neurochem. 35:1092–1098.Google Scholar
  12. 12.
    Spector, R. 1977. Vitamin homeostasis in the central nervous system: Seminar in Medicine. N. Engl. J. Med. 296:1393–1398.Google Scholar
  13. 13.
    Spector, R. 1986. Pantothenic acid transport and metabolism in the central nervous system. Am. J. Physiol. 19:R292-R297.Google Scholar
  14. 14.
    Spector, R., Sivesind, C., and Kinzenbaw, D. 1986. Pantothenic acid transport at the blood-brain barrier. J. Neurochem. 47:966–972.Google Scholar
  15. 15.
    Greenwood, J., Love, E. R., and Pratt, O. E. 1982. Kinetics of thiamine transport across the blood-brain barrier in the rat. J. Physiol. 327:95–103.Google Scholar
  16. 16.
    Spector, R. 1979. Niacin and niacinamide transport in the central nervous system. In vivo studies. J. Neurochem. 33:895–904.Google Scholar

Copyright information

© Plenum Publishing Corporation 1988

Authors and Affiliations

  • Reynold Spector
    • 1
  • DOnald M. Mock
    • 1
  1. 1.Department of Internal Medicine, Pediatrics, and PharmacologyUniversity of Iowa College of MedicineIowa City

Personalised recommendations