  The stability of albumin-bilirubin complex was investigated depending on pH
of solution. It was shown that the stability of complex increases in presence
of Mn(II) ions. It was also investigated the paramagnetic composition of
gallstones by the electron spin resonance (ESR) method. It turned out that all
investigated gallstones contain a free bilirubin radical-the stable product of
its radical oxidation. Accordingly the paramagnetic composition gallstones
could be divided on three main types: cholesterol, brown pigment and black
pigment stones. ESR spectra of cholesterol stones is singlet with g=2.003 and
splitting between components 1.0 mT. At the same time the brown gallstones,
besides aforementioned signal contain the ESR spectrum which is characteristics
for Mn(II) ion complexes with inorganic compounds and, finally, in the black
pigment stones it was found out Fe(III) and Cu(II) complexes with organic
compounds and a singlet of bilirubin free radical. It is supposed that
crystallization centers of gallstones could be the polymer network of bilirubin
radical polymerization in complex with different metal ions earlier discovered
in gallstones.
