EXPERIMENTAL STUDIES ON RENAL TRANSPLANTATION

HISTOLOGICAL STUDIES OF THE BLOOD VESSELS

Abstract

On purpose to study the vascular changes at the rejection reaction of the renal homotransplantation, 153 adult mongrel dogs were used and were divided into 6 groups: (1) Autotransplantation (its ureter was anastomosed to the skin), (2) Autotransplantation (its ureter was anastomosed to the bladder), (3) Homotransplantation (without immunosuppressive treatment), (4) Homotransplantation (treated with Imuran), (5) Homotransplantation (treated with Imuran and Glycyrrhizin) and (6) Homotransplantation (treated with Cobaltiprotoporphylin). The transplanted kidney, the site of anastomosis of renal vessels and ureterovesical anastomosis were histologically examined in each group, and were compared with the angiographic findings.
The following results were obtained:
1) According to the angiography of the renal homotransplantation, there was a diffuse linear deficit of cortical opacification in the nephrographic phase. Corresponding to the deficit, histologically it was found that there were edema and cellular infiltration in the interstitium at the early rejection reaction, and that there were thrombosis of the interlobular arteries and necrosis of the tubulus at the late stage. The former was considered reversible, and the latter irreversible.
2) When Ba. sulfate was poured into the removed kidney, the endothelial cells of the small vessels were stripped off. It was found more frequently in the homotransplantation than in the autotransplantation. According to this result, it was presumed that the endothelial cells of the vessels have already tended to be stripped off on the first day after the homotransplantation.
3) A small aneurysm and arteriovenous shunts were present in the homotransplanted kidney. Apparently it was thought that the aneurysm resulted from the rejection reaction. Arteriovenous shunts were found in the autotransplantation as well as in the homotransplantation, so it could not be asserted that the arteriovenous shunts resulted from rejection reaction, and artificial changes caused by Ba. sulfate could not be denied.
4) Intimal thickening which was frequently found at chronic rejection reaction was not found so frequently in our series as transplanted kidneys were examined at acute and subacute ones. It was found in 9 cases of 56 homotransplanted kidneys. The earliest intimal thickening was present on the fifth day.
Intimal thickening was histologically observed in some anastomosic sires of the renal arteries, but it was considered that the arteries received artificial damages at the operation.
5) The rejection reaction in the vessels of the ureter of a homotransplanted kidney follows the general pattern observed in the respective kidney. Cellular infiltration was found in the ureter, but not in the bladder. Infiltrated cells in the ureter did not migrate through the tissue of the bladder. From the fact, it is considered that the cellular infiltration in the homotransplanted kidney is related in some degree with the antigenicity of the interstitium.
Bone formation at the site of ureteroneocystostomy was observed both in the autotransplantation and in the homotransplantation. So it is not particular to the homotransplantation, and perhaps it may be related to the stream of the urine.
6) Koch's “Sphärolithen” were found in the tubules of the autotransplanted kidney. It is very interesting that “Spharolithen” are considered to be due to vasospasm and that it means autoregulation in the transplanted kidney whose nerves have been intercepted.