The normal human red blood cell, when withdrawn from the circulation, contains a substantial pool of water-soluble organic phosphate compounds, most of which are metabolic intermediates whose concentrations are maintained at constant levels by the glucose metabolism of the cell (1). If blood is stored under blood bank conditions in acid citrate dextrose (ACD) preservative, the organic phosphates of the red cell gradually disappear and inorganic phosphate accumulates. The decline of the organic phosphates coincides with a general deterioration of the cell, for example with a decrease in the glycolytic rate, an inability to concentrate potassium ions and a loss of viability measured by post-transfusion survival (2-4). Several tracted with trichloroacetic acid and the acid was removed with ether. The extract was passed through a 1 X 12 cm. column of Dowex 1-X8 chloride (100 to 200 mesh) which was eluted at 2 ml. per minute with hydrochloric acid and ammonium chloride eluants as indicated in the figures. Fractions of approximately 20 ml. were collected and each was assayed for optical density at 260 m/A and for total phosphorus (9). Spectral measurements at the ultraviolet absorbing peaks indicated that most of the material was adenylate. The anthrone (10), carbazole (11) and orcinol (12) Figure 4 summarizes the changes observed in the phosphate compounds studied as a function of time.The zero time assays revealed several marked differences between the cells collected in ACD in the present study and those red cells collected in heparin anticoagulant (1). Apparently a rapid displacement of the normal equilibrium followed shortly after the blood was mixed with the ACD solution. Actually "zero time" refers to two to three hours of in vitro life for the red cell, mostly at reduced temperature, including the period required for the washing and centrifugation of the 56
planned to study the direct weighing method further in an effort to determine the factors which militate against its use in alloy and ore samples.ACTION WITH ALKALI Kumins found that zirconium mandelate dissolves in sodium hydroxide with the production of zirconyl hydroxide, and in ammonium hydroxide without the production of a precipitate. The halomandelates show this same action. Feigl {2) has pointed out the unusual nature of the reaction of ammonia with zirconium mandelate. This interesting masking action will be studied further from the standpoint both of possible analytical applications and of the isolation of a new class of inner-complex compounds.
The metabolism of sorbitol has been investigated over a period of many years. The sustained interest in this sugar alcohol may be due to the fact that it has been abundantly used in foods and in medicine, and as a close relative of the hexoses, it can throw light on the metabolism of the sugars. Since the ingestion of sorbitol has apparently little effect on the blood sugar (3), it has been recommended by various investigators from time to time as a substitute for sugar in the diabetic diet. However, no information is available regarding the exact insulin requirements of sorbitol. Consequently, we have investigated the metabolism of sorbitol in alloxan-diabetic rats in an attempt to evaluate the role of insulin in its oxidation. It was also desirable to include fructose in these studies since it has been suggested that fructose is a primary oxidation product of sorbitol (1, 4, 9, 10). Glucose was also included for comparison purposes. In all of these studies oral feeding was resorted to, since it has been shown that neither sorbitol nor fructose can be oxidized by the muscle tissues in the absence of the liver and kidneys (14, 15). I n oral feeding practically all of the fed material must pass first through the liver before it is put into the general circulation, in contrast to parenteral injection in which a large fraction of the material is subjected largely to the excretory action of the kidneys before it is made available to the liver. METHODSThe glucose and fructose used in these studies were uniformly labeled with C14 and made by biospnthesis (23). The sorbitol was prepared by the reduction of the labeled glucose (11). All radioactive determinations were carried out on a BaCOs obtained directly or by combustion or by direct count of the material, using a gas flow counter (12).Treatment of animals, Male albino rats weighing approximately 200 g. were made diabetic by the injection of alloxan monohydrate. Only those rats that excreted 15 to 25 g. of glucose per day over a 4-week period when fed a high carbohydrate diet were used. Two diets were employed in these studies, which are referred to as sucrose and fructose diets. Their compositions are as follows: (a) sucrose 6876, casein 15%, yeast 596, salt mixture 496, cod liver oil 5%, and Crisco 6%; and (b) sucrose was replaced by fructose with all other constituents the same. These diets were offered ad libitum during and at least 7 days before the feeding of the radioactive test substances which were administered orally a t the dosage level of 1 g./kilo. Although 26 experiments were carried out, only 7 diabetic rats were used. Since the same rats were used from time to time, the fructose and sorbitol experiments were interspersed between the glucose runs. A minimum of 4 days was maintained between experiments so that there a Presented a t the Symposium on Special Purpose Foods a t the 14th annual meeting of the Institute of Food Technologists, Los Angeles, June 28, 1954.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.