Des cheveux pour évaluer le métabolisme protéique chez l'homme

Perfusing stable (non radioactive) isotope labeled amino acids is used in clinical research to assess protein metabolism. However, it is difficult to apply in clinical practice to adapt protein intake in diseases. A simple, reliable, non-invasive and suitable for clinical use biomarker is missing. We focused on hair 15N hair content as an index of keratin synthesis (the hair protein). Hair is cut close to the scalp, prepared then totally combusted before isotope ratio mass spectrometry analysis. The more intense protein metabolism is, the higher 15N hair content is, because of “isotopic effect”. We recently showed that 15N hair content of the newborn was higher than that of his mother, suggesting a more intense fetal protein metabolism. We are currently working on mechanisms involved in stable isotope natural content of proteins of interest in nutrition. There are many human clinical applications like population's nutritional epidemiology, nutrition in pathology.