Journal of Neural Transmission / General Section JNT

, Volume 102, Issue 2, pp 91–97

Pyridoxine effect on synthesis rate of serotonin in the monkey brain measured with positron emission tomography

  • P. Hartvig
  • K. J. Lindner
  • P. Bjurling
  • B. Långström
  • J. Tedroff
Full Papers

DOI: 10.1007/BF01276505

Cite this article as:
Hartvig, P., Lindner, K.J., Bjurling, P. et al. J. Neural Transmission (1995) 102: 91. doi:10.1007/BF01276505

Summary

The influence of the co-factor pyridoxine, vitamin B6, on the activity of aromatic amino acid decarboxylase enzyme was studied by positron emission tomography, PET in the brain of the Rhesus monkey using the precursor for serotonin synthesis 5-hydroxy-L-tryptophan (5-HTP) radiola-belled with11C in the β-position. The rate constant for the formation of serotonin in the corpus striatum was calculated using a two tissue compartment model with reference area in the brain.

In baseline investigations, the mean rate constants (±S.D:) for selective utilization of [11C]5-HTP to form [11C]serotonin in the corpus striatum was 0.0080 ± 0.0011 min−1. Pretreatment with intravenous pyridoxine hydrochloride 10 mg/kg bodyweight before doing a second PET study resulted in an enhanced rate constant by a mean of 20%. The rate increase was statistically significant. The increase varied considerably in different monkeys from no effect to more than 60%. The effect of pyridoxine on aromatic amino acid decarboxylase activity supported a regulatory role of pyridoxine on the synthesis of neurotransmitter in vivo, and may be of importance in diseases with deficiencies in neurotransmitter function.

Keywords

Serotonin11Cin vivo synthesispyridoxineRhesus monkey

Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • P. Hartvig
    • 1
    • 2
    • 3
  • K. J. Lindner
    • 1
    • 3
  • P. Bjurling
    • 1
    • 2
  • B. Långström
    • 1
    • 2
  • J. Tedroff
    • 4
  1. 1.Uppsala University PET Centre, University HospitalUppsala UniversityUppsalaSweden
  2. 2.The JRDC Subfemtomole Biorecognition project, University HospitalUppsala UniversityUppsalaSweden
  3. 3.Hospital Pharmacy, University HospitalUppsala UniversityUppsalaSweden
  4. 4.Department of Neurology, University HospitalUppsala UniversityUppsalaSweden