Uric acid permeability

Figure 4. Permeability of a phospholipid/cholesterol film for different solutes ascorbic acid (1), tyrosine (2), uric acid (3), acetaminophen (4), cysteine (5), desipramine (6), perphenazine (7), trimipramine (8), promethazine (9), and chlorpromazine (10). (Adapted from ref. 13.)...

By use of myo-inositol and turanose as internal standards, mannitol and lactulose were determined in the present of glucose as their pertrimethylsilylated derivatives during an intestinal permeability test. Purine and pyrimidine nucleosides and bases, and uric acid, all parts of the assembly pheromone of ticks, were detected by g.c.-m.s. analysis of pertrimethylsilylated derivatives using an ion-trap detector. ... 

An artificial kidney, diagrammed below, removes wastes - chiefly urea, creatine, uric acid, and phosphate ions - from blood. Blood passes through tubes permeable to the wastes, and the wastes are absorbed by a dialyzing fluid. In this exercise we consider only the removal of urea. The flow rate of blood through the artificial kidney is 0.200 kg/min. The concentration of urea is 2.15 g urea/kg blood in the input stream and 1.60 g urea/kg blood in the output stream. 

Table 2. The permeability (%) of uric acid through various albumin blended chitosan membranes (6 hour dialysis). 

It appears that the permeability of uric acid is greater in the albumin blended cases compared with the bare chitosan membranes. For this reason, further studies were performed with chitosan albumin blends in the ratio of 7 3, where the maximum permeability rates for these small molecules was observed. It was observed earlier that albumin blended membranes have permeability properties similar to those of other protein blended membranes for the small molecules, although the water content is less here than with the gelatin blends or the bare chitosan membranes. It is possible that many factors govern the permeability of the solutes through the membranes, such as the amount of solute dissolved in the bound water. 

Figure 4. Permeability of urea through various ratios of the albumin blended chitosan membranes (from a mixture of urea, uric acid and creatinine).

The use of other proteins, such as gelatin, collagen, etc., to prepare chitosan blended membranes was tried in a 7 3 ratio (chitosan protein) and the results were compared to the standard cellulose membranes. The permeability, as a function of time, of various molecules, such as urea, creatinine, uric acid, glucose and albumin, through such membranes is shown in Figures 13, 14, 15, 16 and 17, respectively. It appears that the protein blended membranes exhibited improved permeability properties with respect to small molecules compared to the standard cellulose membrane or bare chitosan. These protein blended membranes... 

Hydrophylic films made from albumin for instance are permeable to H2O2 solutions which can be stabilised even by a weak acid such as uric acid. If catalase of high activity is grafted on the out-going face of the membrane, the totality of the oxygen will be liberated from its transporter, namely water. 

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