Enzymes in rat urine. I. A metabolism cage for the complete separation of urine and faeces.
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Acid Phosphatase↗
Biomedical subjects
D T Plummer
Publications and source records attributed to D T Plummer.
The excretion of lacate dehydrogenase in human urine after he ingestion of aspiin.
1. Cells present in normal human urine contain 5-10% of the total lactate dehydrogenase excreted. The enzyme released from these cells by ultrasonication contained a distribution of isoenzymes similar to that found in the bulk of the urine and it is suggested that these cells are the main source of urinary lactate dehydrogenase. 2. Cells were thoroughly washed before examination so it is unlikely that the enzyme found in urinary sediment was simply adsorbed. In addition, full recoveries of added lactate dehydrogenase isoenzymes LDH(1) and LDH(5) showed that adsorption did not occur. 3. Most of the cells in normal urine are of the non-squamous epithelial type and their excretion is greatly increased after the ingestion by the subject of 3g. of aspirin. The possible origin of these non-squamous cells from the kidney is discussed. 4. Starch-block electrophoresis and relative activity measurements of lactate dehydrogenase excreted after the subject had taken aspirin show that the enzymes present in urine and cells are very similar, confirming the conclusion reached above (point 1). They have slightly more M subunits than the normal, shown particularly as an increase in isoenzyme LDH(2). The isoenzyme pattern is like that of the kidney medulla and the possible reasons for this are discussed in terms of the concentration of salicylic acid in various parts of the kidney. 5. The results confirm the previous suggestion that the kidney is the main source of urinary lactate dehydrogenase.
Adsorption↗
Some properties of lactate dehydrogenase found in human urine.
1. Urinary lactate dehydrogenase was concentrated and subjected to starchblock electrophoresis. The isoenzyme pattern obtained was shown to be similar to that of the kidney cortex and medulla but different from that of the bladder and kidney pelvis. 2. The values for the relative activity and Michaelis constant of urinary lactate dehydrogenase were similar to those for kidney cortex and medulla but significantly different from those obtained for bladder and kidney pelvis. 3. The molecular weight of urinary lactate dehydrogenase was estimated by thin-layer chromatogtaphy on Sephadex G-200. The values obtained for several samples of urine ranged from 129 000 to 155 000 and were very close to that of the crystalline rabbit-muscle enzyme (140 000). 4. The question of the possible origin of urinary lactate dehydrogenase is discussed and the conclusion drawn that the kidney and not the plasma is the most likely source.
Chemical Phenomena↗
The electrophoretic behaviour of mitochondria from kidney and liver of rats.
1. The electrophoretic mobility values for mitochondria prepared from rat kidney and liver measured in 0.125m-potassium chloride-0.02m-tris, pH7.4, are: -0.78(s.e.m.+/-0.02)mu/sec./v/cm. (29 experiments) and -1.06(s.e.m.+/-0.01) mu/sec./v/cm. (21 experiments) respectively. 2. These mobility values are unaffected by washing and spontaneous swelling at 25 degrees , indicating a stable electrokinetic surface. 3. The mobility of rat-kidney mitochondria is unaffected by thyroxine-induced swelling, or by the state of hydration of the rat. 4. pH-mobility curves show similar surface ionogenic groups for kidney and liver mitochondria; their isoelectric points are pH3.9 and pH4.4 respectively.
Animals↗
Assessment of renal injury by urinary enzymes.
The use of serum enzymes in the detection of tissue damage due to disease or toxins is now well established but the full potential for the use of urinary enzymes to detect and monitor kidney damage has not been realized. There are a number of problems involved in dealing with urinary enzymes and these have not always been fully appreciated by research workers. This report discusses some of the difficulties and how they can be overcome.
Acetylglucosaminidase↗