Phenol red excretion test

Certain substances can be excreted through the renal tubules, such as p-amino hippuric acid and phenol red. The maximum clearance rate for these substances was measured to measure the secretory function of the renal tubules. Clinically used phenol red excretion test to check the excretory function of renal tubules. Basic Information Specialist classification: urinary examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: fasting Tips: Do not drink more water before injecting phenol red, otherwise artificially increase residual urine. Normal value Percentage of urine excretion (%): 15min25～50; 30min15~25; 60min10~15; 120min5; The total excretion rate is 60-85. Clinical significance (1) Mainly observe the excretion rate of 15 min and 30 min. Generally, 15 minutes is not less than 25%, and a total of 30% in 30 minutes can be regarded as normal. (2) The phenol red excretion decreased when the kidney itself was lesioned, indicating that the renal mono原 function was impaired. Low results may be diseases: malignant small artery kidney, multiple myeloma, contrast nephropathy, chronic nephritis precautions caused by primary malignant hypertension in the elderly Do not drink more water before injecting phenol red, otherwise artificially increase residual urine. There is evidence that phenol red excretion is not affected by urine volume, and 50% to 60% phenol red can be excreted in 5 to 10 ml of urine. Inspection process (1) Specimen collection: Drinking water is about 500ml, and after 10min, the urine is discarded. Intravenous injection of 1 ml of 6 mg/ml phenol red solution was recorded. Urine was collected once at 15, 30, 60 and 120 min after injection. (2) Determine the amount of each urine, transfer it to a 1L volumetric flask, add 10ml of 100g/L sodium hydroxide solution, add water to the mark, and mix. If the color is light, it can be diluted to 500ml or 200ml or 100ml. The result is divided by 2, 5 or 10 in order. (3) Take another 4 tubes of similar size to the standard size, and add the appropriate amount of diluted urine sample to compare with the standard series tube to obtain the percentage of phenol red excretion per urine sample. (4) Colorimetric: 0 point was corrected with distilled water, the absorbance was read at 560 nm colorimetric, and the percentage of phenol red excretion was found from the standard curve. The mixture was mixed, and the absorbance values ​​of the respective tubes were measured by using distilled water at 0, 560 nm, and plotted as a standard curve. Not suitable for the crowd There are no taboos. Adverse reactions and risks No.