[Comparative study of the effect of free and combined glucose and fructose on the absorption and retention of calcium].
Many carbohydrates play an important role in the process of absorption of several inorganic compounds, particularly of calcium, as shown by FOURNIER. VAUGHAN and FILER have proved that all carbohydrates are equally active under particular conditions: the difference of their action on calcium absorption is related to their absorption speed rate. Fructose appears in an intermediate situation between rapidly and slowly absorbed oses according to Cori's classification based on rates of absorption. In order to examine more closely the extent of differences of carbohydrates on calcium absorption, we chose to compare the action of free and combined fructose with that of carbohydrates found in normal feeding. Six months old rats in a state of calcium equilibrium received orally 2 ml aquous mixture containing 0,01 mM/ml calcium supplemented by 0,12 mu Ci 45 Ca and 0,075 mM/ml carbohydrate. The rats were divided into groups according to the carbohydrate they received, which was one of the following: D-glucose, D-mannose, D-fructose, L-sorbose, maltose, lactose, sucrose, starch, glycogen or inulin. Both absorption and retention of calcium were observed. A coefficient of absorption of 45Ca and the specific radioactivity of bone were established by the measurements of radioactivity of blood samples, which were taken 1 1/2 hour, 3 hours and 24 hours after ingestion, of intestinal content and feces, and of a femur after nitroperchloric mineralization. The results showed that values of absorption coefficient and of specific radioactivity are high for slowly absorbed sugars (mannose, sorbose, lactose) but are very low for free glucose or for glucose easily released by intestine enzymatic activity. Free fructose possesses in intermediate activity equivalent to that of inulin. However, sucrose administered at the same concentration has little effect on calcium absorption.
D000042:Absorption; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004040:Dietary Carbohydrates; D005632:Fructose / Q000494:pharmacology*; D005947:Glucose / Q000494:pharmacology*; D006003:Glycogen / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D007785:Lactose / Q000494:pharmacology; D008297:Male; D008320:Maltose / Q000494:pharmacology; D008358:Mannose / Q000494:pharmacology; D011134:Polysaccharides / Q000494:pharmacology*; D051381:Rats; D013013:Sorbose / Q000494:pharmacology; D013213:Starch / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013395:Sucrose / Q000494:pharmacology
D004040:Dietary Carbohydrates; D007328:Insulin; D011134:Polysaccharides; D005632:Fructose; D013395:Sucrose; D008320:Maltose; D013213:Starch; D006003:Glycogen; D005947:Glucose; D007785:Lactose; D013013:Sorbose; D008358:Mannose; D002118:Calcium
Etude comparée de l'effet du glucose et du fructose libres et combinés sur l'absorption et la rétention du calcium