Doris Rolf

A Modified Diphenylamine Procedure for Fructose or Inulin Determination

Summary A modification of Harrisons diphenylamine method for fructose or inulin determination is described, heating being carried out at 75°C for 60 minutes. With this procedure the ratio of fructose to glucose color production is 64, as compared with a ratio of 8 at 100°C for 30 minutes. Inulin hydrolysis is complete, the standard error of the method is less than 1 percent, the color is light stable and the low color production by glucose permits one to omit fermentation except in the presence of unusual glucose fluctuations.

Renal function and metabolism after relief of unilateral ureteral obstruction.

Renal handling of electrolytes and water may be altered following the relief of obstructive uropathy with increased excretion of salt and water. Mechanisms proposed to explain this increased salt and water excretion include retention of solutes (1), production of a natriuretic material during obstruction (2), and expansion of the extracellular fluid volume (3). In addition, it has been postulated that structural damage to the kidney may also play a role in the altered handling of electrolytes and water (2). Recent observations demonstrating increased fractional excretion of salt and water following release of unilateral ureteral obstruction in experimental animals (4) indicated that structural damage or some other intrinsic change within the kidney may be responsible for the altered electrolyte and water handling. The presence of a contralateral normal kidney during the period of obstruction would prevent extracellular fluid volume expansion and solute retention during the period of obstruction, and thus exclude these as major factors in the altered excretory pattern of electrolytes and water. It has been suggested that structural alterations such as flattening of proximal tubular microvilli (5) will decrease the total luminal surface area of the epithelial cells which makes contact with the tubular fluid and thereby decrease tubular reabsorption (2). Of interest is the fact that certain histochemical alterations are observed following obstruction. Alkaline phosphatase has been found to be greatly reduced (6, 7) while glucose-6-phosphate dehydrogenase and 6-phosphogluconic dehydrogenase activities were increased in the proximal tubules of obstructed kidneys (8). Following release of obstruction the activity of these enzymes remained elevated during the initial 48 hr and returned to normal 6 days postobstruction. Decreases in Na-K ATPase activity also have been described following obstruction of 48-72 hr duration (9). Despite these observations, little attention has been paid to the possible role of renal metabolic alterations in the handling of electrolytes and water following relief of obstruction.

A Rapid Micro Method for Determining Diodrast and Inorganic Iodide Iodine in Blood and Urine.

The present paper describes a rapid micro method for the determination of diodrast or inorganic iodide iodine in whole blood, blood cells, plasma or urine. Hundreds of determinations of diodrast and inorganic iodide added to water, to urine and to filtrates have shown substantially a 100% recovery. With the method in its present form not all of the iodine is recovered from some other iodine compounds investigated, skiodan, iodeikon and isoiodeikon. The method has not been applied to normal blood or urine. The diodrast and skiodan used in this work were kindly furnished by the Winthrop Chemical Company; the iodeiokon and isoiodeikon by the Mallinckrodt Chemical Company. Principles of Method. The iodine-containing sample is digested in an acid solution of potassium permanganate, the iodine thereby being oxidized to iodate and the organic matter destroyed. The excess permanganate is reduced by addition of nitrite and the excess nitrite then destroyed by urea. The iodate is then titrated against a standard 0.0004715 N thiosulphate solution in the presence of an excess of potassium iodide. Procedures. With urine the determination is carried out on a diluted sample. With plasma it may be done either on 0.1 cc (or less, depending on iodine content) of plasma or on a sample of plasma filtrate. Because of their higher organic matter content it has not been found practicable to digest unprecipitated whole blood or cells; these determinations must be done on filtrates, where most of the organic matter has been removed. While determinations can be carried out on unprecipitated plasma, we usually use plasma filtrates, particularly at low iodine levels, since with these an amount equivalent to a larger amount of plasma can be used. With urine no precipitation is ever required.

Effects of Hypophysectomy on Some Renal Functions.

We have reported 1 that diodrast (D) and inulin plasma clearances are markedly reduced in hypophysectomized dogs. It was not determined whether the low D clearance was due to a low renal plasma flow (RPF) or to a diminished renal extraction of D, or to both. The present paper reports on the effects of “simple” hypophysectomy (section of stalk with removal of dependent gland) and of complete hypophysectomy (includes destruction of median eminence) on D plasma clearance, plasma D extraction, RPF, tubular extraction of D, maximum tubular excretory rate for D (D Tm), inulin clearance, filtration fraction and blood volume. It also reports on the question of glomerular intermittence after hypophysectomy, with the finding that intermittence does not occur. Since no certain difference in effects of simple and of complete hypophysectomy was observed on any of the processes studied, no distinction will be made in the present report: the effects are apparently due to loss of anterior lobe, although further observations are required before a final statement can be made. Six dogs have been studied; pre-hypophysectomy observations of most of the processes studied were made on the same animals. Diodrast plasma clearance. In 15 post-hypophysectomy clearance periods on 3 dogs (K6. K10 and K11) taken at 7 to 93 days after operation, D plasma clearance has averaged 141 cc/min./M2, where the normal was 258. The clearance of one completely hypophysectomized dog (K8) on the 4th postoperative day was 155, normal 222; a “simple hypophysectomy” dog (K9) on the 3rd day showed 191 cc/min./M2, where normal had been 208. One dog (K1), with a normal clearance of 232, had a unilateral nephrectomy on 7/22/40 and a simple hypophysectomy on 7/26/40; on 9/4/40 her D clearance was 107.

Modified method for determination of certain organic iodine compounds, inorganic iodide in plasma and urine.

A method for the determination of diodrast and inorganic iodide iodine in blood and urine was presented previously. 1 The principles involved were acid permanganate digestion of the sample with oxidation of iodine to iodate, nitrite reduction of the permanganate, destruction of excess nitrite with urea, and titration of the iodate with thiosulphate in an excess of potassium iodide. This procedure could be carried out either by hand heating of the individual tubes over a micro burner or by heating a number of tubes in a boiling water bath. The digestion of individual samples by hand yields accurate results but requires the constant attention of the analyst. The water bath digestion, however, involves some error, particularly in the digestion of plasma filtrates at high iodine levels, and it is sometimes more difficult to remove all of the permanganate because some manganese dioxide adheres firmly to the walls of the tubes. It is shown here that with an alkaline permanganate digestion these difficulties with the water bath heating are eliminated. With an alkaline digestion more permanganate must be used, and a longer heating period allowed than with the acid digestion. In order to keep down the volume of the digest at time of nitrite treatment and at subsequent titration, preliminary evaporation of filtrate samples is carried out. Procedure. Reagents: 13% trichloracetic acid (A.R.), 72% sodium hydroxide (A.R.), approximately 0.4 M potassium permanganate, 4 N sulfuric acid, 1.0 M sodium nitrite, 5 M urea, granulated potassium iodide, 1 % starch, 0.0005 N sodium thiosulfate or 0.0025 N sodium thiosulfate. Apparatus: circular test-tube rack, water bath, 18×150 mm test tubes, dropping bottles, burette calibrated to 0.01 cc or 0.05 cc. In preparing the potassium permanganate make a 7% solution, boil for 5 to 10 minutes and let stand for at least 24 hours.

Comparison of total body and tissue losses of sodium and chloride with losses from sucrose space in salt-depleted rats

When about 30% of total body Na and Cl is removed from normal adult rats by intraperitoneal dialysis, the external loss of Na and Cl measured 24 hours later is adequately accounted for by loss from ECF (sucrose space). Only small amounts of Na and Cl enter ECF from gastrointestinal contents and bone. Conclusions drawn from muscle and skin samples agree with that from whole body. Such depleted animals remain almost in water balance. Evidence is presented that sucrose space is an equally valid measure of ECF in normal and in depleted animals.