The antiparkinsonian efficacy of grafts of cell aggregates from the extra-adrenal chromaffin Zuckerkandl's paraganglion (ZP) was described in the laboratory, by using the intranigral model in rats (Fernández-Espejo et al. J Neuroscience, 21:9888-9895, 2001). The objective was to discern the neuroregenerative effect of intrastriatal grafts of ZP cells in the retrograde model of parkinsonism in rats. Two types of grafting procedures were employed, based on either ZP cell aggregates or dispersed cells. Findings revealed that grafting ZP cell aggregates (not dispersed cells) into the 6-OHDA-induced denervated striatum was able to ameliorate motor deficits of parkinsonian rats (motor asymmetries, akinesia and bradykinesia), leading to a local regeneration of the striatal tissue (as revealed through TH-ir augmentation) without stopping neuronal degeneration in the substantia nigra. Striatal TH-ir density was found to be 8% lower than that of normal rats (without significant differences) while value was 39.4% lower in sham-grafted parkinsonian animals (p<0.01). Sprouting of spared dopaminergic fibers within the striatum would explain this effect. A significant number of chromaffin cells survived both grafting procedures in the long-term, although more cells were grafted as aggregates. Since ZP chromaffin cells express GDNF and TGF-b1, two neurotrophic factors that protect dopaminergic neurons from degeneration, the neurorestorative action of both factors could account for the striatal regeneration of the host tissue that was observed after grafting ZP cell aggregates.

Supported by grants to EFE from MEC (SAF2002-01689), and Plan Andaluz de Investigacion (CVI127).