CHROMAFFIN CELL-SURVIVAL FROM BOTH YOUNG AND OLD DONORS IS ENHANCED BY COGRAFTS OF POLYMER-ENCAPSULATED HUMAN NGF-SECRETING CELLS

FOLLOWING polymer-encapsulation, human nerve growth factor-secreting b aby hamster kidney fibroblasts (BHK-hNGF) were implanted into the stri atum of hemiparkinsonian rats together with unencapsulated adrenal med ullary chromaffin cells from either young (2 weeks) or old (12 months) donor rats. Animals receiving both BHK-hNGF cells and chromaffin cell s exhibited significant decreases (39-56%) in apomorphine-induced rota tional behaviour which was equivalent regardless of the age of the don or tissue. Histological analysis revealed that while survival of chrom affin cells without hNGF support was poor, co-grafts of adrenal medull a and BHK/hNGF cells increased chromaffin cell survival by 20 times. A gain, this effect was independent of the age of the donor tissue. Retr ieved capsules contained numerous viable encapsulated BHK-hNGF cells w hich continued to release hNGF. These results further indicate the pot ential use of intrastriatal implantation of encapsulated hNGF-secretin g cells for augmenting the survival of co-grafted chromaffin cells as well as promoting the functional recovery of hemiparkinsonian rats.