Distribution of NGF and receptors p-75 in experimental end-to-side neurorraphy

The role and the evidence of neurotrophins in end-to-side neurorraphy is still controversial. Aim of this study was to demonstrate a retrograde flux of neurotrophic factors (NGF) from the nerve stump that influence the expression of specific receptors (p-75) at the suture site on the donor nerve, which is normally connected to its end-organ. Two groups of animals have been used and a end-to-side connection was done between median and ulnar nerve in the forearm leaving the FCU muscle connected to the ulnar nerve in Group A and disconnecting the donor complex in Group B. We found that high levels of NGF arc present in the median nerve, in the ulnar nerve, at the suture site and in the muscle and that NGF activity at 2 and 7 days was less in group B, where the ulnar (donor) nerve was disconnected from its target organ (FCU) in comparison to group A.