The relation between amylase retention and excretion and non-protein nitrogen retention in experimental uranium nephritis / R. Fitz, M.D. Boston.

  • Fitz, Reginald, 1885-1953
Date:
1915
Catalogue details

Licence: In copyright

Credit: The relation between amylase retention and excretion and non-protein nitrogen retention in experimental uranium nephritis / R. Fitz, M.D. Boston. Source: Wellcome Collection.

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    the histological examination in Zenker’s fluid and were stained with eosin and methylene blue. In the second series of experiments, the nephritis was allowed to run its natural course. The non-protein nitrogen of the blood and the amylase of the urine were determined periodically. Amylase in the blood serum could not be estimated so often on account of the anemia induced from such frequent and relatively large bleedings. The rabbits were kept in metabolism cages of moderate size. They were fed with carrots, oats and water. Each rabbit consumed about 100 gm. of carrot and 50 gm. of oats per day except for a few days at the height of the nephritis. In addition each rabbit was given 50 c.c. of water by stomach tube every morning to insure as constant an out¬ put of urine as possible. The urine specimens from the metabolism cages were collected in receivers which contained 10 c.c. of toluol as a preservative. Every morning, the animals’ bladders were emptied by massage and the urines so obtained were added to the containers to complete the twenty- four hour specimens. The amylase readings in both urine and blood serum were made by the method of Wohlgemuth and Noguchi.19 In brief, this depends on determining the amount of starch which is converted to dextrin or lower products by a known amount of urine or blood at a given temperature during a given interval of time. Iodin is used as an indi¬ cator of the starch digestion. Wohlgemuth has taken for a unit which he calls “d” the number of cubic centimeters of .1 per cent, soluble starch solution digested in one-half hour by 1 c.c. of urine or blood serum at a temperature of 38 C. “D” is the number of cubic centi¬ meters of starch solution digested by the twenty-four hour urine. Rosenthal in obtaining the “absolute diastatic strength” of urine has preferred to divide Wohlgemuth’s “D” reading by 2. In the experiments with urine both “d” readings and the “absolute diastatic strength” were recorded to show the effect of dilution on the excretion of amylase. This question has been discussed by various observers. Wynhausen,10 Corbett,13 Rosenthal,11 Von Benczur9 and Geyelin14 found that the influence of dilution on “d” readings was lim¬ ited and without effect in the range of normal twenty-four hour urines., although allowance must be made when the quantities were abnormally large or small. In the experiments reported, such marked variations in urinary output occurred from day to day that the necessity of con¬ sidering the effect of dilution was obvious. 19. Wolgemuth and Noguchi: Berl. klin. Wchnschr., 1912, xlix, 1096. This method is described in detail by Geyelin (Note 14) and therefore the descrip¬ tion is not repeated here.