Direct analysis of neuropeptides by in situ MALDI-TOF mass spectrometry in the rat brain.
The measure of neuropeptides is an important tool in biology to better define endocrine and neuroendocrine function. Traditionally most methods have relied on the development of specific antibodies. Newer molecular methodologies have used measures of gene expression of neuropeptide precursors, such as Northern blot, PCR or in situ hybridization analysis. Matrix-assisted laser desorption/ionization (MALDI) mass analysis is a novel powerful technique for investigation of neuropeptides. Multiple peptides and peptide forms can be detected simultaneously and with great sensitivity in tissue extracts or partially purified samples. We have now adapted a MALDI methodology for the direct measurement of neuropeptides on fresh tissue sections of rat brains. We have validated the method by examining peptidergic mass profiles of the supraoptic nucleus (SON) and caudate putamen hypothalamic regions. Interestingly, mass profiles showed that vasopressin, which is specifically present in the SON, is modulated when animals are treated with lipopolysaccharides. MALDI-MS on brain slides is a novel complementary technique for neurobiologists and endocrinologists in order to investigate the dynamic and regional distribution of neuropeptides during physiological events.
Laboratoire de Neuroimmunologie des Annélides, UMR CNRS 8017, SN3, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d'Ascq Cedex, France.
Isabelle
I
Fournier
Robert
R
Day
Michel
M
Salzet
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects; D005260:Female; D008070:Lipopolysaccharides / Q000494:pharmacology; D009479:Neuropeptides / Q000032:analysis*; D011699:Putamen / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013495:Supraoptic Nucleus / Q000737:chemistry; D014667:Vasopressins / Q000032:analysis
D008070:Lipopolysaccharides; D009479:Neuropeptides; D014667:Vasopressins