Factors affecting Excretion of Human Urinary Tamm—Horsfall Glycoprotein

Abstract

1. Tamm-Horsfall glycoprotein was determined, by radioimmunoassay, in samples of urine from normal individuals under a variety of physiological conditions. 2. The amount of glycoprotein excreted in 24 h by our population (39 +/- 13 mg, corrected for body surface area) was found not to be influenced by sex, age (19-60 years) or amounts of Ca2+, Mg2+ and Na+ excreted. 3. Urine samples collected at 2 h intervals over 24 h from individuals drinking in response to thirst, contained quantities of the glycoprotein which showed high positive correlations with urine volumes, but not with Ca2+, Mg2+ or Na+ excretion. 4. The amounts of urine and of the glycoprotein were correlated for individuals in antidiuresis, induced by restriction of water intake. Relatively small amounts of glycoprotein were excreted by individuals in states of water-induced diuresis. 5. The amounts of glycoprotein excreted after exercise were positively correlated with the small volumes of urine voided, but they were uninfluenced by the degree of proteinuria or of hyaline cast formation. 6. The half-life for turnover of the glycoprotein in a given individual is highly variable, from a minimum of 3-7 to a maximum of 168 h.

Effect of an isotonic rehydration sports drink and exercise on urolithiasis in rats

“…In several studies urinary THP excretion in stone forming patients was lower than in normal subjects (17,18). In contrast, other studies have shown that average excretion was similar in the various groups studied (19,20). Furthermore, the effects of THP on crystal aggregation can be significantly modified by factors such as THP concentration and the presence or absence of citrate and other ions in the environment.…”

Uromodulin Levels Associate with a Common UMOD Variant and Risk for Incident CKD

“…Future studies should also seek to address the potential impact of additional factors on urinary uromodulin concentrations, such as intraindividual variation, 20 as well as a potential effect of pH and urine concentration. 15,21,22 In summary, the presence of elevated uromodulin levels preceded the development of CKD in our study, and uromodulin levels were associated with a common SNP in the UMOD gene region in two independent study samples. Our findings identify a potentially useful target for diagnostic testing and therapeutic intervention.…”

Uromodulin, an Emerging Novel Pathway for Blood Pressure Regulation and Hypertension

“…It is positively correlated with estimated glomerular filtration rate (eGFR), urine volume, dietary salt, and protein intake. [21][22][23][24] The urinary uromodulin-dietary salt correlation is more prominent in salt-sensitive hypertensive patients. 25 Increased dietary salt in male Sprague-Dawley rats results in increases in relative steady-state mRNA and protein levels of uromodulin in the kidney, suggesting that a sodium-induced increase in urinary uromodulin reflects increased intrarenal synthesis rather than increased urinary shedding.…”

“…8 The human GWASs all consistently show the uromodulin decreasing alleles (of rs12917707, rs4293393, rs13333226) to be associated with higher GFR. [5][6][7][8] Although lower GFR may indicate renal damage and reduced functioning tubular mass resulting in lower urinary uromodulin as seen in clinical studies, 21,22 the single-nucleotide polymorphism-GFR association implies a possible causal association between UMOD variation on GFR. If this were the case, then absence of UMOD in UMOD −/− mice should also show high GFR, but surprisingly, UMOD −/− mice show significantly decreased urinary GFR compared with wild-type mice.…”