The effects of a partial hemitransection at the meso-diencephalic level, with or without chronic
ganglioside GMI treatment, have been evaluated on striatal
polyamine levels, 7, 14 and 21 days after lesion, as well as on the ability of the
polyamine synthesis inhibitor
alpha-difluoromethylornithine (alpha-DFMO) to modulate the protective effects of chronic
ganglioside GMI treatment against
retrograde degeneration of the nigral
dopamine (DA) nerve cell bodies (14 day time interval). The striatal
polyamine levels were measured by high pressure liquid chromatography after dansylation of the
polyamines. The nigral DA nerve cells were studied by means of
tyrosine hydroxylase (TH) immunocytochemistry using the indirect immunoperoxidase technique. Quantitation was performed by means of morphometrical evaluation of the TH immunoreactive area of the substantia nigra. Seven days after partial hemitransection there is a marked increase (above 350%) in striatal
putrescine levels, which is not modulated by chronic GMI treatment. This marked increase could, to a large extent, be counteracted by simultaneous treatment with alpha-DFMO, which blocks mainly the synthesis of
putrescine. Twenty-one days after lesion chronic GMI treatment could produce an increase in striatal
putrescine levels on the intact side and also after this time-interval prevent the reduction of striatal
spermine levels. It was also found that simultaneous treatment with alpha-DFMO prevents the development of the protective action of chronic
ganglioside GMI treatment against
retrograde degeneration of the nigral DA neurons.(ABSTRACT TRUNCATED AT 250 WORDS)