A microangiographic study of renal allograft rejection and the effects of immunosuppression in the rabbit.
Minute renal cortical vascular changes in 14 allografts without treatment, 14 allografts with immuno-suppressive drugs, and 14 control autografts, were studied in rabbits using a quantitative microangiographic technique. The immunosuppressive regimen used was azathioprine 1 mg/kg, cyclophosphamide 1 mg/kg, and methylprednisolone 0.5 mg/kg, daily. The kidney grafts, removed at 2, 4, 6, 8, 10, 12, and 14 days after renal transplantation, were examined histologically and microangiographically . Interstitial mononuclear cell infiltration at two days was observed to almost the same degree in allografts with or without immunosuppressive drugs. In the group without treatment, vasoconstriction of afferent arterioles and interlobular arteries was noted 2 to 4 days after renal transplantation, followed by progressive reduction in glomerular size and number. The vasoconstriction began to recover 6 days after renal transplantation; it is considered to be the first step of the functional disturbance in renal allograft rejection. In the group with immunosuppressive treatment, temporary vasoconstriction of afferent arterioles and interlobular arteries occurred as well. However, subsequent changes at the glomerular level were definitely prevented. These results suggest that immunosuppressive drugs may prevent one of the processes by which infiltrating lymphocytes cause lesions of the glomerular capillary walls.
D000792:Angiography / Q000379:methods; D000818:Animals; D005260:Female; D006084:Graft Rejection; D007108:Immune Tolerance; D007668:Kidney / Q000098:blood supply; D007678:Kidney Glomerulus / Q000473:pathology; D016030:Kidney Transplantation; D008833:Microcirculation; D011817:Rabbits; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous