Chris Chan, MD, FRCPC
Fellow in Nephrology,
University of Toronto
Over the past two decades, the main strategies that have been used to protect patients against the loss of renal function include lowering their blood pressure and restricting the intake of dietary protein. The efficacy of the above treatments has been limited and a novel therapeutic target is required. In the past decade, landmark clinical trials with pharmaceutical agents that inhibit the renin-angiotensin system (RAS) have demonstrated a dramatic attenuation of the decline in renal function that is associated with diabetic and non-diabetic nephropathies. It is now recommended that inhibition of the RAS should be standard care for patients with proteinuric nephropathies.
Theoretical Basis of Renoprotective Benefits of RAS inhibition
Several authors have reviewed this topic in detail and interested readers should review the articles cited in the references.1 The seminal studies were performed by Brenner et al. using the 5/6 nephrectomy animal model.2,3 In these rats, extensive renal parenchyma is destroyed, which results in a compensatory increase in single nephron glomerular filtration rate and in the elevation of glomerular capillary hydraulic pressure. Pathologically, the rats developed focal glomerulosclerosis and proteinuria. This proteinuria was prevented, following treatment with enalapril.
