Analytical and Bioanalytical Chemistry

, Volume 388, Issue 8, pp 1643–1651

Autism and urinary exogenous neuropeptides: development of an on-line SPE–HPLC–tandem mass spectrometry method to test the opioid excess theory

Authors

    • Institute of Functional GenomicsUniversity of Regensburg
    • Department of EntomologyUniversity of California at Davis
  • D. Hanna
    • Department of EntomologyUniversity of California at Davis
  • P. Whetstone
    • Department of EntomologyUniversity of California at Davis
  • R. Hansen
    • Department of Pediatrics, M.I.N.D. InstituteUniversity of California Davis School of Medicine
  • B. D. Hammock
    • Department of EntomologyUniversity of California at Davis
Original Paper

DOI: 10.1007/s00216-007-1301-4

Cite this article as:
Dettmer, K., Hanna, D., Whetstone, P. et al. Anal Bioanal Chem (2007) 388: 1643. doi:10.1007/s00216-007-1301-4

Abstract

Autism is a complex neurodevelopmental disorder with unknown etiology. One hypothesis regarding etiology in autism is the “opioid peptide excess” theory that postulates that excessive amounts of exogenous opioid-like peptides derived from dietary proteins are detectable in urine and that these compounds may be pathophysiologically important in autism. A selective LC–MS/MS method was developed to analyze gliadinomorphin, β-casomorphin, deltorphin 1, and deltorphin 2 in urine. The method is based on on-line SPE extraction of the neuropeptides from urine, column switching, and subsequent HPLC analysis. A limit of detection of 0.25 ng/mL was achieved for all analytes. Analyte recovery rates from urine ranged between 78% and 94%, with relative standard deviations of 0.2–6.8%. The method was used to screen 69 urine samples from children with and without autism spectrum disorders for the occurrence of neuropeptides. The target neuropeptides were not detected above the detection limit in either sample set.

Keywords

AutismNeuropeptidesβ-CasomorphinGliadinomorphinOpioid peptide excess theoryOn-line SPE–HPLC–MS/MS

Abbreviations

ASD

autistic spectrum disorder

DIEA

N,N-diisopropylethylamine

DIPCDI

N,N′-diisopropylcarbodiimide

DMAP

4-dimethylaminopyridine

DMF

N,N-dimethylformamide

Fmoc

9-fluorenylmethoxycarbonyl

HOBt

N-hydroxybenzotriazole

PyBOP

benzotriazole-1-yl-oxy-tris-pyrrolidino-phosphonium hexafluorophosphate

SPE

solid-phase extraction

TIS

triisopropylsilane

Trt

trityl

Copyright information

© Springer-Verlag 2007