Synthesis
of 5-alpha-pregnane-3,20-dione and 5-alpha-pregnane-3-alpha-ol-20-one
in Human Brain Tumors by Hans Joerg Stuerenburg, Hagen Schuhmacher, Frauke Lohmann,
Maximilian Puchner, Ingevild Breivik & Klaus Kunze
Abstract:
In
this study, we have been able to demonstrate the local conversion
of progesterone to DHP and THP in human brain tumors. The enzymatic
activity of the conversion of progesterone to DHP (progesterone-5-alpha-reductase)
in all tumors (n = 38) was 8.09 ± 3.22 fmol/mg protein/min (mean
± S.E.M); the enzymatic activity of the conversion to THP (3-alpha-hydroxysteroid
dehydrogenase) was 2.36 ±0.28 fmol/mg protein/min. Previous
studies on the detection of progesterone receptors in human
brain tumors have until now not taken into consideration the
important factor of the local modification of progesterone effects
in brain tumors by metabolism. The metabolism of progesterone
demonstrated here may lead, on the one hand, to an inhibition
of the local neuronal activity via GABAA-receptor-mediated effects
of the metabolites, and on the other hand, to alterations in
the genomic effects with consequent influences on tumor growth.
