The Constituents of Urine

Phosphate of Soda.—This Balt has long been known as one of the constituents of urine, having been discovered in that fluid by Hellot in 1737. It was not, however, sufficiently distinguished from other Balts, till a much later period, when it was examined and analysed by Proust, Rouelll, and Kdapkotii. 

Almost at the same time Abderhalden (Al) showed the peptide character of the undialyzable part of urine. By means of the Fischer analysis method he isolated from the hydrolyzate of this mixture certain free amino acids, and for the first time introduced the name polypeptide for the analyzed constituent of urine. 

One of the major constituents of urine is the di-amine, urea (III). Each amine group in urea should remind us of ammonia in Equation (6.11). Solutions of urea in water are basic because the two amine moieties each abstract a proton from water, to generate an ammonium salt and a hydroxide ion ... 

Qualitative and quantitative comparisons of the constituents of the urine of male and female white-tailed deer indicated that the presence and concentration of the urinary compounds depend on the season, reproductive status and social rank of the animals [ 132,133]. Of the 63 and 55 compounds characterized in female and male urine, respectively, 27 were common to both sexes, 36... 

In the shape of agricultural produce of a field, the entire amount of those constituents which have become ingredients of plants is removed from the soil. After a series of years, and a corresponding number of harvests, the fertility of the soil or field diminishes. The change which is found to have taken place in the composition of the soil after harvest, is the probable cause of its diminished or lost fertility. By means of solid and liquid manure, or the excreta of men and animals, the loBt or diminished fertility of the land is restored. Solid or farmyard manure consists of decayed vegetal and animal matters, which contain a certain proportion of the constituents of the soil. The excrements of men and animals represent the ashes of the food consumed, and which has been derived from the supposed soil. The urine contains the soluble, the solid excrete the insoluble constituents of the soil derived from the crops used as food, and reaped from the soil. By adding these to the soil, it recovers those constituents which have been removed from it in the crops. 

It seems feasible that traces of heavy-metal ions may have some bearing upon certain features of the action of mammalian /3-glucuronidase, such as the fall in net activity seen on dilution of highly purified preparations (see Section IV), the inhibitory action of the unknown constituents of urine,185 190 and the pH optimum at pH 3.4 observed by Mills, Paul, and Smith166 but by no other workers (see Section VI). The presence of traces of Cu in the assay mixture would provide a completely satisfactory explanation of the variable effects reported with L-ascorbic acid (see Section IX, 2).196s... 

Methylxanthine is the major purine constituent of human urine (3.1 g in 10001) (1898ZPC(24)364). 3- and 7-Methylpurines are also minor constituents of urine, especially following large doses of caffeine or other methylated xanthines. 1,3-Dimethylxanthine (theophylline) occurs with caffeine in tea leaves and is a powerful diuretic and has been used clinically for this purpose (generally as an adduct with salts of organic acids) and also in the treatment of asthma. 1,7-Dimethylxanthine (paraxanthine) is also an efficient diuretic and, in addition, possesses antithyroid properties (45JCS751). The main purine constituent... 

High-resolution analyzers have been used to determine the molecular constituents of urine and blood serum as well as other body fluids, such as cerebrospinal fluid, perspiration, saliva, and amniotic fluid. Well over 300 molecular constituents can apparently be separated by a combination of all four types of analyzers however, many of the separated components have not actually been isolated and identified by spectral and chemical tests. 

In the development of new drugs, HPTLC may offer very interesting features. Contrary to other chromatographic techniques, all the constituents of a mixture are spotted on the plate and can be analyzed, even if they are not identified easily. Therefore, it is possible to determine if and how a given product is broken down or metabolized. For example, nimesulide, a common nonsteroidal antiinflammatory drug (NSAID), was detected in equine blood and urine samples following a race [1]. An unidentified spot was also detected on the same plate. This spot was further identified as a nitro derivative of the active compound. This derivative appeared to be unique to horses. Other published data mention the use of HPTLC alone or in combination with other analytical... 

The Ektachem 700 analyzer has been constructed in such a manner that mechanical parts can be monitored by computer. This results in easy operation, maintenance and problem-free servidng. Colorimetric, potentiometric and kinetic measurements can be performed. All the steps required for the reaction take place in the slides. These enable a quantitative determination of constituents of serum or plasma samples and some constituents of urine or cerebrospinal fluid. The slides are stored in cartridges (Fig. 22) that are sealed in aluminium foil. Each slide can be used for only one assay and is ejected directly after the measurement. 

The type of urine specimen to be collected is dictated by the tests to be performed. Untimed or random specimens are suitable for only a few chemical tests usually, urine specimens must be collected over a predetermined interval of time, such as 1,4, or 24 hours. A clean, early morning, fasting specimen is usually the most concentrated specimen and thus is preferred for microscopic examinations and for the detection of abnormal amounts of constituents, such as proteins, or of unusual compounds, such as chorionic gonadotropin. The clean timed specimen is one obtained at specific times of the day or during certain phases of the act of micturition. Bacterial examination of the first 10 mL of urine voided is most appropriate to detect urethritis, whereas the midstream... 

Certain metabolites of the pyrimidine pathway are excreted in excess of the normal in inherited metabolic disorders of the urea cycle. They include orotic acid, uridine, and uracil. Of these substances, only uracil is a normal constituent of urine, the other two either being absent or present in very small amount. They are readily detected qualitatively as dark bands at the appropriate Rf values when a paper chromatogram of the urine is examined under ultraviolet light. They may be estimated by an ion exchange method similar to that for urinary pseudouridine (R13). 

Grassmann and Schleich have shown by Sorensen s method that ox-skin collagen contains equimolecular amounts of D-glucosamine and D-galactose, and a complex with the same proportions of these constituents has been reported in the protein of the ovalbumic glands of Rana esculenta. The mucoproteins of urine are as yet unexplored except insofar as they are known to contain small amounts of certain of the blood group factors. ... 

Finally, there have been a few studies on the analysis of urinary proteins by ITP (T2, Ul). Clark and co-workers (C5) studied the UV-absorbing constituents of urine from patients with rheumatoid arthritis as compared with osteoarthritis patients and healthy controls and were able to show significant differences (Fig. 5). 

Most of the constituents of normal urine are probably filtered into the kidney nephrons through the glomerulus,11 selective tubular... 

I.I.3. Aconitic Acid. Aconitic acid has been shown to be a constant constituent of urine (N20, 05). The violet color given when sprayed with p-dimethylaminobenzaldehyde (N15) makes its identification easy on paper chromatograms of urinary organic acids. 

It helps to consider firstly Ihe concept of clearance . Consider any plasma constituent which is also present in urine. The amount excreted can be calculated by measuring the urinary concentration ((/, say mmoles per litre) and multiplying that by the volume of urine collected in a given time (V, say litres in a 24h period). 

Dstebmixation of Quantity of Ursa in Urine.—It must not be forgotten that, in all quantitative determinations of coostituente of the urine, the question to be solved is not bow much of that constituent is contained in a given quantity of urine, but how much of that substance the patient is discharging in a given time, usually twenty-four hours. Quantitative determinations are, therefor, in most cases, barren of useful results, unless the quantity of urine passed by the patient in twentr-four hours is known and, in view of diurnal variations in elimination, unless the urine examined be a sample taken from the mixed urine of twenty-four hours. 

According to Kruse, urea is an important constituent of manured soils. Urea CO(NH2)a the chief nitrogenous constituent of urine and the principal end point of tissue metamorphosis is attacked by the urea organisms and converted into ammonia and C02 as ... 

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