Physiological Disposition and Metabolic Fate of Infused Pentoses in Man

Wyngaarden, James Β.; Segal, Stanton; Foley, Joseph B.

doi:10.1172/jci103539

Cited by 107 publications

(58 citation statements)

References 43 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…per mg., respec- The rate constants for the disappearance from blood of the C14 of D-xylose, D-lyxOse and D-and L-arabinose are very similar to those calculated from the curves of disappearance of pentose determined chemically, following infusion of large quantities of sugar. These ranged from 0.77 to 1.58 per cent per minute (10). However, ribose chemically determined has been shown to be cleared from blood with rate constants much larger than the 0.68 recorded for C14.…”

Section: Methodsmentioning

confidence: 91%

“…Previous reports have described the physiological disposition of large quantities of infused pentoses (10), the effect of insulin on blood levels of infused pentoses (11) as well as studies of the metabolism of D-ribose (12). This paper reports some observations on the fate of C14 labeled D-xylOse, D-lyxose, D-arabinose and L-arabinose administered in trace quantities intravenously to normal human subjects.…”

mentioning

confidence: 97%

See 1 more Smart Citation

The Metabolic Fate of C14 Labeled Pentoses in Man

Segal¹,

Foley²

1959

J. Clin. Invest.

Self Cite

View full text Add to dashboard Cite

The role of pentoses in intermediary metabolism has received much attention within the past few years. The phosphate esters of D-ribose, D-ribulose and D-xylulose have been identified as key intermediates in the pentose phosphate pathway of glucose metabolism in both plant and mammalian tissue (1). More recently, another alternate pathway of glucose dissimilation, the uronic acid pathway, has been described in which L-Xylulose, xylitol and D-xylulose are intermediates (2).Several pentoses have been identified in normal urine: the aldopentoses xylose, arabinose and ribose (3, 4) and the ketopentoses D-ribulose and L-xylulose (5). Large quantities of the latter sugar are excreted in the disease essential pentosuria (6, 7), which appears to be due to a defect in the further conversion of L-xylulOse to the sugar alcohol xylitol (8). In addition to L-xylulOse Touster and Harwell (9) have also reported the isolation of L-arabitol from the urine of pentosuric subjects.Because of increasing awareness of the biological importance of the pentoses, certain aspects of pentose metabolism in man have been investigated in this laboratory. Previous reports have described the physiological disposition of large quantities of infused pentoses (10), the effect of insulin on blood levels of infused pentoses (11) as well as studies of the metabolism of D-ribose (12). This paper reports some observations on the fate of C14 labeled D-xylOse, D-lyxose, D-arabinose and L-arabinose administered in trace quantities intravenously to normal human subjects. Some of the previously published data (12) on C14 ribose metabolism are included for purposes of comparison. METHODSFive experiments were performed in four normal male volunteers aged 18 to 21. Each subject had been on a 250 Gm. carbohydrate diet for at least three days and was fasted overnight prior to study.Five /Ac. of each sugar dissolved in 250 ml. of normal saline were infused over a 15 minute period. Expired air samples were collected for 4 minutes at 15 to 60 minute intervals for 6 hours. Urine samples were collected at hourly intervals for 6 hours and pooled thereafter till 24 hours had elapsed from the start of the experiment. A urine sample was obtained at the twentyfifth hour to determine if C" was still being excreted. Urine was preserved by freezing at -20' C. Blood wvas collected at 20 minute intervals.Methods for the collection and C' counting of expired CO,, for preparation and radioactive assay of blood samples, and C' counting and chromatography of labeled compounds in urine have previously been described (12).The C" pentoses D-xylose, D-lyxose, D-arabinose, Larabinose and D-ribose (Figure 1) with specific activity of 0.67, 1.65, 1.65, 1.11, 2.6 and 2.01 ,lc. per mg., respec-H C=O H-C-OH

show abstract

Section: Methodsmentioning

confidence: 91%

mentioning

confidence: 97%

The Metabolic Fate of C14 Labeled Pentoses in Man

Segal¹,

Foley²

1959

J. Clin. Invest.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Experiments have recently been reported describing the dissimilation of infused pentoses in man. 10 D-xylose, D-arabinose, L-arabinose and D-lyxose, when infused intravenously into a normal subject, were observed to disappear slowly from blood. In contrast, D-ribose is cleared from blood at an extremely rapid rate.…”

Section: Pentose Metabolism In Manmentioning

confidence: 96%

“…Little or no effect of pentose infusion on blood pyruvate and lactate has been observed. 10 Decreases of serum inorganic phosphate values have been noted but the significance of this is open to question. The pentoses, however, do produce an alteration in blood glucose levels.…”

Section: Pentose Metabolism In Manmentioning

confidence: 99%

See 1 more Smart Citation

Pentose Metabolism in Man

Segal¹

1958

Diabetes

Self Cite

View full text Add to dashboard Cite

Episodes of disordered behavior, coma or convulsions are not infrequent during the course of severe, chronic, congestive heart failure. When observed, they are usually attributed to some process such as anoxemia, a cerebral vascular disturbance, drug intoxication, electrolyte imbalance, or some other alteration directly or indirectly related to the underlying cardiac disorder. The importance of the early recognition of the remediable causes of such occurrences is obvious, and hence the considerable therapeutic significance of the observation that they may occasionally be due to periods of hypoglycemia, readily reversed by the simple act of administering adequate glucose.

show abstract

Transport of sugars into human red blood cell ghosts

Lacko

1966

Journal Cellular Physiology

View full text Add to dashboard Cite

It has been found that human red cell ghosts react differently in the presence of various sugars in the medium. The stability of spheric ghosts is preserved in solutions of sugars entering red cells by means of the common carrier. In media of other sugars the ghosts' shapes change to shrunken, crenated forms and between the microscope slides to discoid ones. Under the conditions employed it was further observed that the incubation of fructose-or rhamnose-containing ghosts in solutions of sugars sharing the carriers led to an equilibration of sugars between the medium and the ghosts. The impermeability of ghosts for sugars not sharing the carriers was supported by the finding that fructose could be washed out to a much less extent than glucose. These results suggest that sugars without affinity to the carriers may move in the erythrocyte membrane through nonspecific sites (pores, channels).

show abstract

Physiological Disposition and Metabolic Fate of Infused Pentoses in Man

Cited by 107 publications

References 43 publications

The Metabolic Fate of C14 Labeled Pentoses in Man

The Metabolic Fate of C14 Labeled Pentoses in Man

Pentose Metabolism in Man

Transport of sugars into human red blood cell ghosts

Contact Info

Product

Resources

About