The Reaction of the Intrarenal Sympathetic Nervous System to Renal Transplantation

In six autogeneic and three allogeneic canine renal transplants kidney function tests were performed before and after transplantation. The dogs with allografts were given immunodepressive treatment. Both the normal kidneys of the dogs and the transplants were examined histologically and by the histochemical fluorescence method for biogenic monoamines. In no transplant was there evidence of regeneration of the adrenergic nervous system. No significant change in GFR and FF following the transplantation was recorded in the autografts and in two of the allografts in which graft reaction was absent or minimal. In the third allograft GFR and FF were low and the graft reaction fairly advanced. The tubular function of the autografts responded normally to mannitol diuresis. The findings suggest that (i) renal transplantation results in permanent sympathetic denervation of the graft, (ii) normal renal hemodynamic and tubular functions can be maintained after sympathetic denervation, (iii) other mechanisms than direct sympathetic nerve stimuli are responsible for the intrarenal vascular spasm and elevation of plasma renin activity encountered in patients with renal transplants.