What is "oxygen-17"

n. (context isotope English) A rare stable isotope of oxygen, (nuclide 17 8 O), having eight protons and nine neutrons; it amounts to 0.037% of the element in nature

Oxygen-17 is a low abundant isotope of oxygen (0.0373% in seawater; approx. twice as abundant as Deuterium). Being the only stable isotope of oxygen possessing a nuclear spin(+5/2) and a favorable characteristic of field-independent relaxation in liquid water, this enables NMR studies of oxidative metabolic pathways through compounds containing O at high magnetic fields (i.e. metabolically produced HO water by oxidative phosphorylation in mitochondria).