The active transport of sugars by various preparations of hamster intestine

Crane, Robert K.; Mandelstam, Paul

doi:10.1016/0006-3002(60)91482-7

Cited by 306 publications

(117 citation statements)

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“…When the blood glucose concentration exceeds the threshold for glucose excretion, the tubular sites for glucose reabsorption may be saturated and only a small number of transporters may be left available for AG reabsorption; consequently, the AG reabsorption may be reduced or abolished in this situation and AG would be excreted. Support for the plausibility of a common active transporter for AG and glucose has been ,obtained in vitro [15]; AG was effectively transported by the glucose transporter of hamster intestine in an energy-linked manner. The idea of active AG transport also accommodates the efficient ingestion of orally-administered AG demonstrated in rats [8].…”

Section: Discussionmentioning

confidence: 94%

Urinary excretion of 1,5-anhydro-D-glucitol accompanying glucose excretion in diabetic patients

et al. 1988

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Summary.The urinary excretion of 1,5-anhydro-D-glucitol, a pyranoid polyol, in humans was studied. The plasma of nondiabetic human subjects contained high concentrations of this polyol (> 110 ~tmol/1), and there was a tendency for the 24-h excretion of it to become more variable in direct proportion to its plasma concentration. In contrast, diabetic patients showed lower plasma concentrations of this polyol, and the variation in the 24-h excretion of 1,5-anhydro-D-glucitol was especially notable among the patients with an extremely low plasma concentration of the polyol. This diabetic group showed a statistically significant correlation (p<0.01), between the urinary 1,5-anhydro-D-glucitol and urinary glucose. This correlation was more markedly demonstrated during a 100-g oral glucose tolerance test: parallel changes were observed in the concentrations of 1,5-anhydro-D-glucitol and glucose in the urine collected every hour after the glucose load. These observations led to the proposal that low plasma concentration of this polyol, which is observed in diabetes mellitus, may be the result of a frequent and/or prolonged high blood glucose concentration beyond the renal threshold for glucose excretion.Key words: 1,5-anhydroglucitol, urinary excretion, reabsorption, glucosuria, hyperglycaemia.A pyranoid polyol resembling glucose, 1,5-anhydro-Dglucitol (AG), is a humoral component in humans and other mammals [1][2][3][4][5][6][7][8][9][10][11][12]. The plasma AG concentration is specifically reduced in diabetes mellitus [10] and shows several dynamic properties which are advantageous as a clinical marker for diabetes mellitus. First, the extent of the plasma AG reduction is apparently correlated with the severity of diabetes mellitus, and strict metabolic control can reverse this reduction [11]. Second, AG undergoes very slow turnover in vivo [8,12], and its plasma concentration remains stable over a 24-h period, showing little acute response to fasting, food intake, and insulin administration [11]. Finally, AG also shows chemical and biochemical stability [12], and accordingly, we found no significant limitation on the storage and transport of plasma samples for AG determination. On the other hand, the utility of the plasma AG concentration as a clinical marker is certainly limited by a lack of metabolic knowledge: the origin and clearance mechanism of AG in humans have not yet been established. Recently, we demonstrated the primary role of renal AG reabsorption in AG retention in rats and mice [12]. That study also indicated a possibility that the diabetic plasma AG reduction is due to a decrease in renal AG reabsorption. In order to evaluate in humans the role of renal function in AG retention in the circulation, we measured the urinary AG and urinary glucose as well as the plasma AG and blood glucose. Subjects and methods SubjectsStudy 1. The amounts of AG and glucose in the blood and in a 24-h urine sample were determined for 11 non-diabetic volunteers and 30 diabetic patients, which included two patients with Typ...

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Section: Discussionmentioning

confidence: 94%

Urinary excretion of 1,5-anhydro-D-glucitol accompanying glucose excretion in diabetic patients

et al. 1988

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“…Most of these studies for uptake, me tabolism and transport of substrates by intestinal epithelial cells have been performed on isolated preparations immersed in physiological salt solution, e.g., intestinal rings, sheets of mucosa and serosa, and isolated villi (1)(2)(3). Although these preparations provided pertinent information leading to investigations of biochemical problems related to absorption and metabolism of drugs, there were drawbacks.…”

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confidence: 99%

Vascularly perfused rat small intestine: A research model for drug absorption.

et al. 1980

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Abstract-Rat isolated small intestine was perfused at a fixed flow rate through the superior mesenteric artery with whole rat blood recycled from a devised oxygenator reservoir. As indicated by perfusion pressure, tissue glucose and oxygen consumption, and histological studies, the perfused intestine remained in a viable state over the perfusion period of 2 hr. Rapid absorption of glucose from the intestinal tract was observed after the intraduodenal injection. When single doses of acetaminophen were injected into the duodenal lumen or poured over the perfused intestine, the ab sorption was rapid and dose-dependent.Shortly after single intraduodenal injections of salicylamide, salicylamide in free and conjugated forms (sulfate and glucuronide) appeared in the circulating blood. These results indicate that the vascularly perfused intestinal preparation has wide applications in biochemical experimental fields.Numerous investigations have been concerned with attempts to develop useful pre parations for evaluating functions of the intestine. Most of these studies for uptake, me tabolism and transport of substrates by intestinal epithelial cells have been performed on isolated preparations immersed in physiological salt solution, e.g., intestinal rings, sheets of mucosa and serosa, and isolated villi (1-3). Although these preparations provided pertinent information leading to investigations of biochemical problems related to absorption and metabolism of drugs, there were drawbacks. Kavin et al. (4) and Windmueller et al. (5) devised an isolated intestinal preparation of the rat sustained by vascular perfusion with washed bovine red blood cells suspended in an "artificial plasma" and with rat whole blood, respectively, then carried out studies on viability. Their preparations appeared to be parti cularly suitable for examining entry of drugs from the intestinal tract into the blood or lymph vessels. However, most of the studies pertaining to drug absorption and metabolism have not been carried out in such preparations, and to our knowledge there is only one study, recently reported, which dealt with absorption of antipyrine, salicylic acid and urea (6).Thus, we examined absorption and metabolism of several drugs in the intestine, using the rat isolated small intestinal preparation sustained by perfusing the mesenteric vasculatures with whole rat blood recycled from a devised oxygenator-reservoir. MATERIALS AND METHODSMale Sprague-Dawley rats (130-150 g) were deprived of food overnight before the

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“…The present results with metabolic inhibitors indicate that this transfer is energy coupled and in that sense truly an active process. Furthermore, it is interesting that the same inhibitors (including the requirement for sodium) that antagonize the transport of a simple small molecule like glucose in intestines of other animals inhibit the transfer of large complex molecules in our system (Crane & Mandelstam, 1960;Czaky & Thale, 1960;Crane, 1962;Bihler & Crane, 1962).…”

Section: Discussionmentioning

confidence: 99%

“…In contrast, gut from the unfed neonatal piglet seems devoid of potentially interfering substrates, although it has sufficient endogenous energy for transport. It is possible that the neonatal piglet derives its energy for active transport from the same source as the unfed hamster; namely, the endogenous energy may come from non-carbohydrate metabolites such as fat or fatty acids (Crane & Mandelstam, 1960).…”

Section: Discussionmentioning

confidence: 99%

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In vitro absorption of γ‐globulin by neonatal intestinal epithelium of the pig

Lecce¹

1966

The Journal of Physiology

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SUMMARY1. An in vitro method, using fluorescent y-globulin and everted neonatal pig's intestinal slices, for the study of the active transport of large molecules is described.2. Uptake of y-globulin occurred within 15 min and required no exogenous substrates.3. In vitro absorption of y-globulin by intestinal epithelium was limited to the neonatal pig and 5-day-old mouse. No uptake was seen in intestines from a mature mouse, a pig with diarrhoea, a normal pig, a mature rabbit, a guinea-pig, a chick, and a chick embryo. Chick embryo yolk sac readily took up y-globulin.4. Rings of everted intestinal epithelium remained active (still absorbed y-globulin) after incubating for 4-6 hr in balanced salt solution (BSS).5. Uptake of y-globulin required oxygen and sodium and was reversibly inhibited by metabolic antagonists such as iodoacetate, arsenate, fluoride, 4,6-dinitro-o-cresol, phlorrhizin, anaerobiosis and cold. Underthe conditions of the test, large colloidal molecules did not inhibit uptake of y-globulin.6. Similar results (although not as clear-cut) with metabolic inhibitors were obtained with preparations of chick embryo yolk sacs.7. Injuring mature pig's intestinal epithelium with surface-active agents did not produce non-specific absorption artifacts that resembled the specific absorption found in immature pig's intestinal epithelium.

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The active transport of sugars by various preparations of hamster intestine

Cited by 306 publications

References 43 publications

Urinary excretion of 1,5-anhydro-D-glucitol accompanying glucose excretion in diabetic patients

Urinary excretion of 1,5-anhydro-D-glucitol accompanying glucose excretion in diabetic patients

Vascularly perfused rat small intestine: A research model for drug absorption.

In vitro absorption of γ‐globulin by neonatal intestinal epithelium of the pig

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