The comparative rates of absorption of sugars from the human intestine

Abstract

HOPPE-SEYLER [1881] and Heidenhein [1894] first drew attention to the fact that simple physical laws could not explain the absorptive phenomena in the intestine. Hober [1899] compared the rates of absorption of several sugars and salts and found that dogs absorbed galactose slightly faster than glucose. Hedon [1900] compared the rates of absorption of glucose, fructose, galactose and arabinose from a loop of rabbit's gut. He found that from a 25 % solution arabinose was absorbed most quickly and then in order galactose, glucose and fructose. From isotonic solutions glucose was absorbed most rapidly. Working with "Vella" fistulae on a series of four dogs Nagano [1902] found that the monoses showed characteristic relative rates of absorption. Galactose was most rapidly absorbed and then in order glucose, fructose, mannose, xylose and arabinose. Solutions over 10 % were not used. Hewitt [1924] compared the rates of absorption of dilute solutions of glucose, fructose and galactose from loops of gut. In rabbits no very conclusive results were obtained, but in cats glucose was absorbed much more rapidly than fructose, while galactose occupied an intermediate position. All were absorbed at equal rates after killing the intestinal mucosa by hot liquids or sodium fluoride. Cori [1925], using standard rats, administered by stomach-tube a strong solution of the sugar to be tested and subsequently killed the animals after varying intervals, and the sugar still left in the whole of the alimentary tract was estimated. This method was an improvement on the older ones in that intact animals could be employed. Large numbers of rats moreover could be used and the results averaged. Cori placed the sugars in the same order as Nagano and found their relative rates (glucose =--100) to be: galactose 110, glucose 100, fructose 43, mannose 19, xylose 15, and arabinose 9. Macleod [1929] has recently criticised one or two points in Cori's technique, and Magee and Macleod [1929] have determined the rates of diffusion of sugars through isolated oxygenated loops of rabbits' intestine. No more definite conclusions were drawn than that hexoses were absorbed more rapidly than pentoses.

The Effect of Insulin on Blood Levels of Infused Pentoses in Man

“…Table III presents the total urinary excretion of pentoses in the experiments described, plus several others. The total excretions are in the range reported for normal subjects not receiving insulin (17,18). Two studies are shown in which the excretion of infused sugar was measured in the same individual, both when insulin was given and omitted.…”

Physiological Disposition and Metabolic Fate of Infused Pentoses in Man

“…Attempts to follow C14 excretion in later urine specimens showed that no more than 0.2 per cent of the administered isotope appeared on days 2 or 3. (41,60), and with limited animal data obtained with D-xylose in dogs (43) and rabbits (61,62), and with L-arabinose in rabbits (63). It is of interest also that intravenously administered L-xylulose is well utilized by the dog, Xylose excretion has been carefully studied at a renal level.…”

Integrative physiology of transcellular and paracellular intestinal absorption

“…Intestinal glucose absorption has been studied for nearly a century (e.g. McCance and Madders, 1930;Wertheimer, 1934), and the modern view that it is driven predominantly by Na + -coupled glucose absorption across the apical, or brush border, membrane of enterocytes especially emerged in the three decades beginning in the 1960s (Table 1). In the past three decades, knowledge on the mechanisms of intestinal glucose absorption has continued to advance, partly thanks to the existence of alternative views that include an important paracellular pathway.…”