Measurement of endogenous leucine enkephalin in canine thalamus by high-performance liquid chromatography and field desorption mass spectrometry.
A combination of high-performance liquid chromatography and field desorption mass-spectrometry is used to quantify endogenous amounts of leucine enkephalin in canine thalamus tissue. Reversed-phase high-performance liquid chromatography effects rapid high resolution of brain neuropeptides using a triethylamine formate buffer. An internal standard, 2Ala-leucine-enkephalin, is used. Field desorption mass spectra of neuropeptides generally display only protonated molecular ions. (M + H)+ ion currents of endogenous leucine enkephalin and internal standard were integrated by field desorption mass spectral-selected ion monitoring techniques. The ratio of the two integrated ion currents was used to calculate endogenous amount of leu-enkephalin in thalamus tissue extracts. Leucine enkephalin was determined in this structurally unambiguous fashion in canine thalamus tissue at 50 ng/g thalamus tissue, or the 50 part per billion level.
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D004723:Endorphins / Q000032:analysis*; D004745:Enkephalins / Q000032:analysis* / Q000378:metabolism; D013058:Mass Spectrometry; D012016:Reference Values; D013788:Thalamus / Q000378:metabolism*
D004723:Endorphins; D004745:Enkephalins