Kidney transplantation in mice using left and right kidney grafts

Mouse kidney transplantation is a powerful tool for scientific research. The conventional method uses only the left donor kidney for grafting because of shorter renal vessels on the right side.

We developed a new technique of harvesting both left and right kidneys from one donor mouse, and separately transplanted them into two recipients. Forty-six kidney grafts (23 left, 23 right kidneys) were transplanted to 46 recipient mice. Life-supporting kidney transplantation (in which both recipient kidneys were removed) was performed in 12 recipients (six of each group).

Cold ischemia times were considerably longer for the second kidney graft (2.5-3 versus 1 h), which resulted in reduced graft function at early time points. However, the 14 d survival rate was comparable with 80% for right and 70% for left kidney grafts. Recipient animals were sacrificed between 1 and 6 wk after transplantation. Histologic examination of surviving grafts showed intact renal parenchyma, whereas total necrosis was usually seen in failed grafts. The causes of graft failure were thrombosis of the renal artery, narrow outflow of the renal vein, and fistula of the ureter. In a subgroup of animals, specific staining for apoptosis was performed. A tendency for a higher rate of apoptosis was seen at 1 wk compared with 6 wk post-transplant, but no correlation with cold ischemia time was found.

We report a new microsurgical technique of mouse kidney transplantation using both right and left donor kidneys as grafts for two recipient mice. Right kidney grafts showed equal survival compared with left kidney grafts. Thus, this technique reduces overall operating time and costs for microsurgery experiments.