A Porcine Model of Calcium Oxalate Kidney Stone Disease

ABSTRACTPurpose: The pig has been extensively used in biomedical research because of the similarities in organ structure and function to humans. It is desirable to have an animal model of oxaluria and urolithiasis with physiological, anatomical and nutritional characteristics that more closely resemble those of man. In this study we determined if feeding pigs trans-4-hydroxy-l-proline (HP) increased urine oxalate levels and if it would serve as a model for human hyperoxaluria and stone disease.Materials and Methods: Male Yorkshire-Durox cross-bred pigs were fed HP for up to 20 days. Urine was periodically collected and analyzed for oxalate levels and the presence of crystalluria. After 20 days of feeding the kidneys were removed and examined grossly and microscopically for indications of injury, crystal deposition and stone formation.Results: Feeding pigs 10% HP (weight per weight HP/food) produced hyperoxaluria, which reached a maximum and leveled off by day 6. Urine oxalate remained near this level unti...