The study of alterations of mitochondrial DNA transcription could be o
f Fundamental interest to understand the molecular mechanisms underlyi
ng the impairment of mitochondrial function in liver diseases related
to hepatocyte energy production. We show that isolated normal human li
ver mitochondria, when incubated in the presence of [alpha-P-32]UTP in
an appropriate incubation medium, in which the energy requirements ar
e provided by exogenous ADP in the presence of oxidizable substrates,
are able to support RNA synthesis in a way faithfully resembling the i
n vivo process. The autoradiographic pattern in agarose-methylmercury
hydroxide gels of the newly synthesized RNA shows the presence of all
the previously described RNAs coded in the mitochondrial genome (ribos
omal, messenger and transfer RNAs). We conclude that this system could
be of great value to investigate the role of the mitochondrial genome
on human liver pathology related to mitochondrial damage.