Profiling of urinary medium-sized peptides in normal and uremic urine by high-performance liquid chromatography

This report describes the profiling of medium-sized peptides in both normal and uremic urine by ion-pair reversed-phase high-performance liquid chromatography using an acetonitrile—heptafluorobutyric acid solvent system as eluent. Several medium-sized peptide peaks could be detected in both normal and uremic urine at low picomole level by using post-column fluorescence derivatization with fluorescamine. Contrary to expectation, uremic urine contained slightly larger amounts of medium-sized peptides compared with normal urine.     

Interleukin 1 activity in normal human urine

Human leukocyte dialysates contain components capable of amplifying cutaneous delayed-type hypersensitivity (DTH) reactions. In the present study, two such amplifiers, both less than 3500 m.w., were partially purified from human leukocyte dialysates by gel filtration on Sephadex G-10 followed by high pressure reverse-phase liquid chromatography. These amplifiers of DTH were examined for their effects on production of the migration inhibitory lymphokines leukocyte migration inhibition factor (LIF) and macrophage migration inhibition factor (MIF). The amplifiers were found to increase LIF and MIF production by antigen- or alloantigen-stimulated human peripheral blood lymphocytes in a dose-dependent fashion. Further analysis demonstrated that although antigen-stimulated T4 and T8 cell subpopulations could produce LIF activity under the assay conditions employed, amplification of lymphokine production by modulator was only observed with the T4 subset.     

An alpha-L-fucopyranosyl-myl-inositol in normal human urine.

An α-$\text{L}$-fucopyranosyl-$\text{myo}$-inositol has been isolated from normal urine of ABH-secretors. The compound was also present in small amounts in the urine of ABH-non-secretors. After ingestion of 20 g of $\text{myo}$-inositol, two secretors increased their excretion of α-$\text{L}$-fucopyranosyl-$\text{myo}$-inositol three and thirteen times respectively. The same $\text{myo}$-inositol diet did not give rise to any increased excretion of α-$\text{L}$-fucopyranosyl-$\text{myo}$-inositol in the urine of two non-secretors.     

Variation of metabolites in normal human urine

Urine is often sampled from patients participating in clinical and metabolomic studies. Biological homeostasis occurs in humans, but little is known about the variability of metabolites found in urine. It is important to define the inter- and intra-individual metabolite variance within a normal population before scientific or clinical conclusions are made regarding different pathophysiologies. This study investigates the variability of selected urine metabolites in a group of 60 healthy men and women over a period of 30 days. To monitor individual variation, 6 women from the normal population were randomly selected and followed for 30 days. To determine the influence of extraneous environmental factors urine was collected from 25 guinea pigs with similar genetics, diet, and living environment. For both studies, 24 metabolites were identified and quantified using high-resolution ¹H nuclear magnetic resonance spectroscopy (NMR). The data demonstrated large inter and intra-individual variation in metabolite concentrations in both normal human and control animal populations. A defined normal baseline is essential before any conclusions may be drawn regarding changes in urine metabolite concentrations.     

The heterogeneity of arylsulphatase-A and arylsulphatase-B in normal human urine and urine from cancer patients

Arylsulphatase-A and arylsulphatase-B heterogeneity in normal and cancer patient urine was investigated using high resolution agarose isoelectricfocusing. Normal urine contained up to nine forms of arylsulphatase-A activity with isoelectric points from 4.45 to 5.43 and at least 5 forms of arylsulphatase-B between 8.58 and 9.15 along with a broad zone of activity between pH 6.5 and 7.6. Although cancer patients had significantly higher levels of arylsulphatase-A and arylsulphatase-B activity, their pattern of activity was essentially the same as for the normals with only minor quantitative differences in some peaks.     

Tight junctions are sensitive to peptides eliminated in the urine

We prepare an extract of dog urine (DLU) that, when applied to monolayers of MDCK cells (epithelial, derived from a normal dog), enhances the transepithelial electrical resistance (TER) in a dose-dependent manner. This increase is not reflected in variations of the linear amount of TJ nor in changes of the pattern of junctional strands as observed in freeze fracture replicas, nor in the distribution of claudin 1 (a membrane protein of the TJ) nor ZO-1 (a TJ-associated protein). A preliminary characterization of the active component of DLU indicates that it weighs 30-50 kDa, bears a net negative electric charge, and is destroyed by type I protease but not by 10-min boiling. DLUs prepared from human, dog, rabbit and cat are effective on MDCK cells. However, dog DLU increases TER in MDCK (dog) as well as LLCPK1 (pig) monolayers, but not in other epithelial cell lines such as LLCRK1 (rabbit), PTK2 (kangaroo) and MA-104 (monkey), nor in the endothelial cell line CPA47 (cow). Given that in its transit from the glomerulus to the urinary bladder the filtrate increases its concentration by more than two orders of magnitude, the substance(s) we report may act at increasingly higher concentrations in each segment, and afford a potential clue to the progressive increase of TER across the walls of the nephron from the proximal to the collecting duct.     

Determination of proteins in unconcentrated normal human urine

The protein content of repeatedly dialyzed urine is determined by measuring its absorbancy at 210 nm.