  Klein-Gordon equation is derived for a particle in the brane model of
Universe. It is compared with squared Dirac-Fock-Ivanenko equation and
expression for a chiral current is obtained by this comparison. This expression
defines chiral current through variation of spin connection gauge field that
arises due to the symmetry in respect to local Lorenz transformations. So, the
second derivative of gravitational gauge field determines variation of chiral
current responsible for variation of mass. The role of these processes on the
early stages of Universe evolution is discussed.
