Renal surrogates in essential hypertension.

The kidney can be considered both as culprit and victim in the hypertensive process. Renal functional derangement contributes to the development of arterial hypertension and the development of secondary vascular damage both at the glomerular and arteriolar level accounts for the development of progressive nephrosclerosis. The most common alteration of renal function observed in humans since the early stages of essential hypertension is the presence of renal vasoconstriction. This can be accompanied by the appearance of hyperuricemia, increased urinary excretion of enzymes such as N-acetyl-beta- glucosaminidase and of proteins like albumin and beta2-microglobulin. Later on, a progressive fall in glomerular filtration rate accompanied or not by proteinuria can be observed if high blood pressure persists.