Non-sugar Reducing Substances Research Articles

Evaluation of an Automated Glucose-Oxidase Procedure

We evaluated a slight modification of the automated oxidase/peroxidase method for glucose determination in blood with use of 4-aminophenazone [J. Clin. Pathol. 22, 246 (1969)]. Nonsugar reducing substances did not interfere, except for ascorbic acid in very high concentrations. Lipemic sera gave slightly lower values. Values for reproducibility, specificity, and sensitivity were closer to such values for the hexokinase method than was the case for some other commonly used methods.

Quantitative analysis of serum and urine sugars by gas chromatography

A method for the quantitative determination of serum and urinary sugars by gas-liquid chromatography of their trimethylsilyl ethers is described. The method is fast, sensitive and like the glucose oxidase method emphasizes the absolute values since non-sugar reducing substances can be distinguished. Sugars other than glucose may be determined conveniently, e.g., galactose, mannitol, fructose, inositol, pentoses, etc. An example of a mannitol clearance test is presented illustrating the ease of analysis. Agreement between gas chromatography and a glucose oxidase method for 15 random serum samples was satisfactory. Average recovery of added glucose for 10 samples was 97.1%.

Use of Ion-Exchange Resins for the Removal of Nonsugar Reducing Substances in the Analysis of Fresh Leafy Plant Materials for Sugars

Use of Ion-Exchange Resins for the Removal of Nonsugar Reducing Substances in the Analysis of Fresh Leafy Plant Materials for Sugars

QUALITATIVE AND QUANTITATIVE DETERMINATION OF THE WHEAT LEAF CARBOHYDRATES

The nonreducing sugar in wheat leaves is probably entirely sucrose. It is the only abundant sugar. Free reducing sugars are absent, or almost absent from wheat leaves grown under the conditions described. The reducing power in the cleared alcoholic extracts of the leaves is, at least, partly due to degradation products of ascorbic acid. Other nonsugar reducing substances also are apparently present. The alcohol insoluble residue from wheat leaves contains little or no fructosan, dextrin, or starch at the two and one-half week old stage. Satisfactory methods for extracting and determining the sucrose are described. The following methods gave satisfactory results with wheat leaf extracts: the reducing power methods of Hanes and Somogyi after acid or preferably invertase hydrolysis, Ost's solution for fructose residues, the method of Neuberg and Strauss, the colorimetric resorcinol method. The latter method gives only approximate values for fructose residues unless the sugar concentration is high; the method is then fairly reliable. The following methods did not give satisfactory results: Hanes and Somogyi methods for free reducing sugars initially present in the extract, the hypoiodite titration for aldose sugars, and Sieben's method for fructose determination.

DARK REACTIONS OF CHLOROPLAST SUSPENSIONS

Chloroplast suspensions from the majority of plant species produce titratable acidity in darkness when mixed with ferricyanide – ferric oxalate solution. The rate of production and yield of acid increases between pH 6.0 and 7.5. This oxidation–reduction requires the presence of ferricyanide or ferric oxalate and does not involve enzymes. The nonsugar reducing substances in chloroplast suspensions which participate are water-soluble, and may include ascorbic acid, glutathione, and tannins. By applying a correction for dark acid production, photochemical activity in chloroplast suspensions showing this reaction may be measured by the Holt and French titration method. Boiled leaf sap of Broad Windsor bean produces carbon dioxide rapidly when mixed with ferricyanide – ferric oxalate solution, apparently by oxidative decarboxylation. Crude chloroplast suspensions from this species also exhibit oxygen absorption and dark acid production. Simultaneous measurement of these reactions shows no evidence of quantitative relations. The precipitation of oxalate causes an alkaline drift in pH when crude chloroplast suspensions of Lycopodium or Sedum are mixed with Hill solution in darkness. With crude spinach chloroplast suspensions, interference by dark reactions in photochemical activity measurements is generally negligible.

Starvation hypoglycemia in late pregnancy

The Gibson (Folin-Wu) method for blood sugar gives results comparable to those obtained with the Somogyi (Shaffer-Hartmann) technic. Both methods evidently exclude the determination of nonsugar reducing substances, and therefore apparently give true sugar values.In pregnant women near term starvation for twelve hours leads to blood sugar reductions similar to those observed in nonpregnant individuals, but fasting for fifty hours reduces the blood sugar to levels considerably below those recorded for the nonpregnant. In 14 among 53 such patients the blood sugar fell to less than 40 mg. per cent, and in one case to 30 mg. per cent.Development of a marked starvation hypoglycemia with acetonuria produces no signs or symptoms of toxemia of late pregnancy, except that mild transient headaches are occasionally noted.Starvation for fifty hours in the last month of pregnancy is frequently (30 per cent) followed by the (otherwise spontaneous) onset of labor.

The Micro Determination of Blood Sugar

A technically simple and rapid procedure for the determination of the blood sugar which gives results which are little, if at all, affected by the non-sugar reducing substances of the corpuscles and plasma is presented. The problem of non-sugar reducing substances has been approached in 2 ways—by using copper solutions which are effective on the glucose of the blood only (Folin, S. R. Benedict) and by obtaining protein-free filtrates from which the non-sugar reducing substances are removed along with the protein (Somogyi). The second procedure is obviously the more practical, and is attained in our methods by increasing the proportion of tung-state and sulfuric acid in relation to the volume of blood precipitated.Dr. J. S. Boyd (1923), working in this laboratory, adapted the Folin-Wu method for finger-tip blood specimens to meet the increase in the number of blood-sugar determinations necessitated by insulin control of diabetics. We are now doing over 4200 blood sugar determinations yearly in the routine ...

The non-sugar reducing substances of human blood in pathological conditions

The non-sugar reducing substances of human blood in pathological conditions

The non-sugar reducing substances of human blood, with special reference to glutathione

The non-sugar reducing substances of human blood, with special reference to glutathione

Fate of Glucose and Other Sugars in the Eviscerated Animal.

Rats fasted previously for 24 hours were operated upon under amytal anesthesia. The whole intestinal tract, including spleen and pancreas, and occasionally kidneys and adrenals, was removed. The blood sugar falls in such a preparation owing to the fact that the liver is out of circulation. The sugar content of the whole rat was determined by passing the heat coagulated tissues through a meat grinder and extracting them with hot water. Separation of sugar from non-sugar reducing substances was attempted. Sugar (100 mg. per 100 gm. rat) was injected intravenously after evisceration and groups of rats were killed and analyzed, (a) 10 minutes after the sugar injection, (b) after 1 hour of sugar injection at a constant rate, and (c) after 1 hour of sugar injection plus insulin. The average percentages of sugar recovered in the 3 cases are shown in the following summary: The specificity of the insulin action is a very striking phenomenon. In experiments with injection of larger amounts of sugar and extending over 2 hours, glucose, in the absence of insulin injection, was found to disappear to the same extent as the other sugars. The glycogen content of the muscles increased under these conditions.

DISTRIBUTION OF BLOOD SUGAR BETWEEN CORPUSCLES AND PLASMA IN DIABETIC AND IN ALIMENTARY HYPERGLYCEMIA

It has been demonstrated that the generally accepted view of an equal or nearly equal distribution of sugar between corpuscles and plasma in human blood is erroneous. 1 The evidence was based on true sugar values, obtained as the difference between apparent sugar (total reduction) and nonsugar-reducing substances. It has long been known that nonfermentable substances constitute a part of the sugar values estimated by the usual reduction methods, but—owing to reasons set forth elsewhere 2 —these substances eluded quantitative determination to such an extent that some investigators asserted that almost half of the reduction of protein-free filtrates of normal blood is due to nonfermentable constituents, while others denied altogether the existence of such substances. A simple procedure devised by me, involving fermentation by means of thoroughly washed yeast, permits the rapid and complete removal of fermentable sugars from blood and other biologic fluids, and thus the accurate determination of nonfermentable reducing substances