Prolonged Survival of Fetal and Adult Skin Homografts

Abstract

The postnatal growth and development of neonatal kidneys transplanted into adult recipients was studied in seven animals. An en bloc dissection including both kidneys, aorta, vena cava, and ureters was carried out in puppies 11–53 days of age and placed in the right groin of an adult recipient. The aortic segment was interposed in the right external iliac artery and proximal end of the vena cava was anastomosed to the proximal end of the common iliac vein. Ureterovesicle continuity was reestablished by ureteroneocystostomy. Immunosuppression was maintained postoperatively and the animals were serially studied by intravenous urography and renal-clearance tests. The polar diameter of the kidneys increased as much as 2-fold. Glomerular filtration rate rose from 11 ml/min at 40 days of age to 32 ml/min at 83 days of age. Over the same period effective renal plasma flow increased from 31 ml/min to 110 cc/min. On the other hand, tubular function as measured by tubular reabsorption of sodium, potassium, and phosphate per 100 ml of glomerular filtrate was normal throughout the period studied. We conclude that (1) neonatal kidneys grow and develop normally even when allotransplanted and subjected to immunosuppressive therapy, (2) renal excretory mechanisms for maintaining homeostasis are mature when corrected for GFR even at an early age, (3) neonatal kidneys can support life in an adult recipient. Neonatal kidneys, therefore, are a feasible source of donor organs for transplantation in children and adults.