  Using the AdS/CFT correspondence, we investigate a nucleon mass splitting and
nucleon-pion coupling in the isospin medium. We find that there exists a
nucleon mass splitting which is exactly given by the half of the meson mass
splitting because nucleon has the half isospin charge of the charged mesons. In
addition, we also investigate the nucleon-pion coupling, which requires the
modification of the known Abelian-type unitary gauge fixing term because
non-Abelian fluctuations should be taken into account in the isospin medium. In
this paper, after constructing an appropriate unitary gauge fixing term, we
find that in spite of the nucleon's and meson's mass splittings, there is no
nucleon-pion coupling splitting in the isospin medium.
