Immunoenzyme assay of glial fibrillary acidic protein for evaluation of functional activity of cell grafts from embryonic ventral mesencephalon in rats with experimental hemiparkinsonism

The relationship between the release of glial fibrillary acidic protein (GFAP) into systemic circulation and the efficacy of transplantation of embryonic nervous tissue was studied on rats with 6-OHDA-induced hemiparkinsonism. It was found that intrastriatal transplantation of cell preparations from embryonic ventral mesencephalon significantly attenuated apomorphine-induced rotation, which points to functional recovery of the dopaminergic nigrostriatal system. The degree of this recovery depends on reactive astrogliosis around the graft and survival of dopaminergic neurons. Analysis of GFAP concentration revealed significant elimination of this antigen into the circulation 7 and 14 days after transplantation. In rats with good consolidation of the graft without pronounced reactive gliosis, the concentration of GFAP reached 253.99+/-79.30 ng/ml on week 4 after transplantation and decreased to 8.2+/-3.3 ng/ml 8-12 weeks after transplantation. In rats with poor graft consolidation associated with death of transplanted neurons and gliosis in the graft and surrounding tissue the concentration GFAP increased to 476.4+/-111.0 ng/ml within 4 weeks after transplantation and remained elevated (235.0+/-44.8 ng/ml) for 12 weeks. Thus, monitoring of serum GFAP concentrations allows in vivo evaluation of the functional state of intracerebral graft and the level of reactive gliosis. This test can be used for the prognosis of transplantation efficacy.