Effects of candesartan on the proteinuria of chronic glomerulonephritis

Angiotensin I-converting enzyme (ACE) inhibitors are commonly used for the treatment of hypertension, progressive chronic renal disease, diabetic nephropathy, and congestive heart failure. Because angiotensin II acts through membrane bound type 1 (AT1) and type 2 (AT2) receptors, ACE inhibitors and angiotensin II-receptor antagonists have distinct effects. ACE inhibitors inhibit production of angiotensin II thus suppressing the action of angiotensin II on both AT1 and AT2. In contrast, the effect of AT1-receptor antagonists is to selectively block the activation of the AT1 receptor. This AT1-receptor blockade leaves the AT2 receptors unopposed to elevated levels of endogenous angiotensin II. Thus, there may be an advantage of AT1-receptor blockade over ACE inhibition in the management of a variety of chronic vascular diseases, including chronic glomerulonephritis and other glomerular diseases. In a clinical trial candesartan, an AT1-receptor antagonist, effectively lowered urinary protein excretion in patients with chronic glomerular nephritis. Evidence indicates that functionally active AT1 receptors, as well as AT2 receptors, are present in both afferent and efferent arteriole of the glomerulus, and that angiotensin II induces afferent and efferent arteriolar dilatation via AT2 receptors.