Neural Degeneration and Regeneration in Human Renal Transplants

Neural degeneration and regeneration were studied histologically with hematoxylin-eosin and Bodian stains in 33 human renal transplants. By the fifteenth day after transplantation few intact axons were recognizable, and by the twenty-sixth day, only axonal debris remained. As early as the twenty-eighth day, regenerating axons appeared distal to the graft's arterial anastomosis. Regenerating axons could be traced to the nerves accompanying the interlobular arteries, but the axon population did not reach the number observed in normal nerves of comparable size. Allografts and isografts exhibited comparable patterns of neural regeneration. The development of progressively more exact means of identifying adrenergic and cholinergic nerves has led to an increased interest in determining the role of these nerves in renal function.^{1, 2} This interest has been heightened by the broader use of the renal isograft and allograft in the management of clinical renal insufficiency and by the search for a relation between the function of the graft and the integrity of its autonomic innervation. The fluorescence method of Falck¹ for adrenergic nerves was used by Norvell, Weitsen and Sheppek³ in their study of five human renal allografts. In four allografts examined between 18.