Renal kallikrein and PGE in the exaggerated fractional Na excretion in patients with chronic renal failure.

The present study was performed to investigate the roles of renal kallikrein and prostaglandin (PG) E in the mechanism of the exaggerated fractional Na excretion in hypertensive patients with advanced renal disease by means of the determination of urinary excretion of kallikrein and PGE, and fractional Na excretion in 20 healthy volunteers and 41 patients with chronic glomerulonephritis (14 normotensive patients; 9 borderline hypertensive patients; 18 sustained hypertensive patients). Urinary excretion of kallikrein and PGE was significantly decreased in patients with sustained hypertension as compared with healthy volunteers, while not decreased in those with normotensive or borderline hypertensive patients. Four times higher values for the fractional Na excretion and four or five times higher values for the urinary excretion of PGE corrected for creatinine clearance, were found in patients with borderline or sustained hypertension. There was a significant positive correlation (r = 0.6777) between the two. These results suggest that PGE in the renal tubular compartment may be involved in the mechanism of the exaggerated fractional Na excretion in patients with advanced renal disease. The urinary excretion rate of kallikrein corrected by creatinine clearance was three times greater in patients with borderline hypertension, but no significantly increase in those with sustained hypertension compared with that in healthy volunteers. There was no significant correlation between the fractional Na excretion and urinary kallikrein excretion corrected for creatinine clearance.