Reduction of proliferating non-neuronal cells in dried nerve segments partly impairs nerve regeneration

To determine whether drying of nerve grafts can affect axonal outgrowth and proliferation of non-neuronal cells, nerve segments dried for 0-60 min wer e used as nerve grafts to bridge a gap in transected rat sciatic nerves. Ax onal outgrowth was measured by pinch reflex test and confirmed by immunocyt ochemical staining of neurofilaments. The proliferation of non-neuronal cel ls was measured by incorporation of BrdU in the dried nerve segments. Dryin g of the nerve segment for 60 min reduced the length of axonal outgrowth to 66 and 76% 3 and 6 days, respectively, after the grafting procedure. At th at time point the number of proliferating cells was reduced by 51%. It is c oncluded that the number of proliferating nonneuronal cells is reduced in d ried nerve segments which only partly impairs axonal outgrowth. Factors oth er than Schwann cells are probably important for an optimal mileue for rege neration in nerve grafts. (C) 2000 Lippincott Williams & Wilkins.