title: Metabolism of fatty acids and lipid hydroperoxides in human body monitoring with Fourier transform Infrared Spectroscopy.
abstract: BACKGROUND
  The metabolism of dietary fatty acids in human has been measured so far using human blood cells and stable-isotope labeled fatty acids, however, no direct data was available for human peripheral tissues and other major organs. To realize the role of dietary fatty acids in human health and diseases, it would be eager to develop convenient and suitable method to monitor fatty acid metabolism in human.
  
  
  RESULTS
  We have developed the measurement system in situ for human lip surface lipids using the Fourier transform infrared spectroscopy (FTIR) - attenuated total reflection (ATR) detection system with special adaptor to monitor metabolic changes of lipids in human body. As human lip surface lipids may not be much affected by skin sebum constituents and may be affected directly by the lipid constituents of diet, we could detect changes of FTIR-ATR spectra, especially at 3005 to approximately 3015 cm(-1), of lip surface polyunsaturated fatty acids in a duration time-dependent manner after intake of the docosahexaenoic acid (DHA)-containing triglyceride diet. The ingested DHA appeared on the lip surface and was detected by FTIR-ATR directly and non-invasively. It was found that the metabolic rates of DHA for male volunteer subjects with age 60s were much lower than those with age 20s. Lipid hydroperoxides were found in lip lipids which were extracted from the lip surface using a mixture of ethanol/ethylpropionate/iso-octane solvents, and were the highest in the content just before noon. The changes of lipid hydroperoxides were detected also in situ with FTIR-ATR at 968 cm(-1).
  
  
  CONCLUSIONS
  The measurements of lip surface lipids with FTIR-ATR technique may advance the investigation of human lipid metabolism in situ non-invasively.
authors.affiliation: Dept Biomol Sci, Fac Eng, Gifu Univ, Gifu, Japan. xyosida@gifu-u.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoshida
authors.forename: Qin-Zeng
authors.initials: QZ
authors.lastname: Zhang
authors.forename: Shu
authors.initials: S
authors.lastname: Sakuyama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Matsushima
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D053000:Analytic Sample Preparation Methods; D004281:Docosahexaenoic Acids / Q000008:administration & dosage / Q000032:analysis; D004435:Eating; D015118:Eicosapentaenoic Acid / Q000008:administration & dosage / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008046:Lip / Q000737:chemistry* / Q000378:metabolism; D050356:Lipid Metabolism; D008054:Lipid Peroxides / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000378:metabolism; D012997:Solvents; D013024:Soybean Oil / Q000008:administration & dosage; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation; D013499:Surface Properties; D013997:Time Factors; D055815:Young Adult
chemical_list: D005227:Fatty Acids; D008054:Lipid Peroxides; D012997:Solvents; D004281:Docosahexaenoic Acids; D013024:Soybean Oil; D015118:Eicosapentaenoic Acid