[Neurotropism to tissue specificity in nerve regeneration: an experimental study on the sciatic nerves of the rat]

A study of neurotropism in nerve regeneration was carried out on 44 rats, using their left sciatic nerves severed to work up. The cut ends of proximal and distal stumps were separately introduced into amend of the specially designed silastic tube of Y- or cross-shape. Into the other ends of the tube were inserted either the end of the distal stump or a cut end of achilis tendon on the same side, or were left empty. The distance between the tissue ends, nerve-to-nerve or nerve-to-tendon, was 4 mm. Four weeks later, it was found in the specimens that the growth of neurofibers sprung out from the end of the proximal stump directed towards the distal nerve stump rather than towards the tendon end or the vacant limb of the tube. This fact strongly speaks for that there is some thing neurotropic factor, guiding the direction of growth of the newly formed neurofibers, a property of tissue specificity. The mechanism of neurotropism, the effect of the distance between the cut ends of the nerve and the choice of the silastic material were discussed.