Adenine‐induced chronic kidney disease in rats

Many animal models have been developed to study the causes and treatments of chronic kidney disease (CKD) in humans, an insidious disease resulting from kidney injury and characterized by persistent functional decline for more than 3 months, with or without evidence of structural deficit. The eventual outcome of CKD may be end-stage kidney disease (ESKD), where patients need dialysis or transplantation to survive. Cardiovascular disease is accelerated in patients with CKD and contributes to increased mortality, with the relationship between CKD and cardiovascular disease being bi-directional. Most animal models do not mimic the complexity of the human disease as many do not develop CKD-associated cardiovascular disease. The adenine diet model of CKD in rodents is an exception. The original adenine diet model produced rapid-onset kidney disease with extensive tubulointerstitial fibrosis, tubular atrophy, crystal formation and marked vessel calcification. Since then, lower adenine intake in rats has been found to induce slowly progressive kidney damage and cardiovascular disease. These chronic adenine diet models allow the characterization of relatively stable kidney and cardiovascular disease, similar to CKD in humans. In addition, interventions for reversal can be tested. Here the key features of the adenine diet model of CKD are noted, along with some limitations of other available models. In summary, the data presented here support the use of chronic low-dose adenine diet in rats as an easy and effective model for understanding human CKD, especially the links with cardiovascular disease, and developing potential therapeutic interventions.