Urine and plasma levels of uroguanylin and its molecular forms in renal diseases.

H Kinoshita, S Fujimoto, M Nakazato, N Yokota, Y Date, H Yamaguchi, S Hisanaga, T Eto

First Department of Internal Medicine, Miyazaki Medical College, Japan.

Kidney international 1997 Oct

filter terms:

Uroguanylin activates the intestinal and possibly the renal guanylate cyclase C receptor, and stimulates Cl- secretion. We developed a sensitive radioimmunoassay (RIA) for human uroguanylin and measured its concentration in the urine and plasma. Twenty-four-hour urinary excretion of immunoreactive (ir-) uroguanylin for persons with a high-salt diet (10 g/day) was 137.8 +/- 14.4 pmol/day, significantly higher than that for persons with a low-salt diet (7 g/day, 95.1 +/- 16.3 pmol/day, P < 0.05). There were significantly positive correlations between the urinary excretion of ir-uroguanylin and Na+, Cl-, K+ or cyclic GMP (cGMP). We demonstrated the presence of messenger RNA of guanylate cyclase C in the medulla of human kidney. The concentration of plasma ir-uroguanylin significantly correlated with that of serum creatinine (r = 0.71, P < 0.001). Biologically active uroguanylin-16 accounted for 99% of the endogenous uroguanylin molecules in normal urine and 60% in plasma, the remainder being the 10 kDa precursor. The precursor content increased in the urine and plasma as the severity of renal impairment increased. These findings suggest that bioactive uroguanylin-16 is involved in the regulation of electrolyte homeostasis and that the kidney participates in the metabolism and excretion of uroguanylin.

Citation

H Kinoshita, S Fujimoto, M Nakazato, N Yokota, Y Date, H Yamaguchi, S Hisanaga, T Eto. Urine and plasma levels of uroguanylin and its molecular forms in renal diseases. Kidney international. 1997 Oct;52(4):1028-34