Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.108 (lactase)
 2,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The gastric emptying of maltose, sucrose, lactose and lactulose was compared in young adult rats with ontogenic lactase deficiency. Eight animals were employed for each sugar meal at each time of study (total number of animals = 192). Each animal received a test meal consisting of a solution of the sugar (100 mg/ml) and phenol red as marker and gastric retention was measured at 5, 10, 20, 30, 45 and 60 min after orogastric infusion of the test meal. Gastric retention was determined by measuring the concentration of the marker in the residual test meal recovered from the stomach after killing the animal. There was no difference between the gastric emptying of lactose and lactulose. The gastric emptying of maltose was significantly slower during the initial 30 min and the emptying of sucrose was identical to that of maltose only at 5 min and could not be distinguished from that of lactose and lactulose at later times. These data support the observation, made in human subjects, that, under conditions of ontogenic lactase deficiency, the modulation of gastric emptying of lactose is ineffective. It is possible that the rapid emptying of sucrose is due to the saturation of sucrase because of substrate overload which impairs the intestinal inhibitory control of gastric emptying.
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PMID:Gastric emptying of maltose, sucrose, lactose and lactulose in rats with ontogenic lactase deficiency. 182 68

The gastric emptying of sucrose and maltose solutions at different concentrations, with addition of phenol red (6 mg%) used as a marker, was studied in 144 Wistar male rats. The gastric retention was determined 15 minutes after the orogastric infusion of sucrose and maltose solutions at 2.5%, 5% and 10% and volume of 1 and 2 ml/100 g weight of the animal, making 1 use of 12 rats for each volume and concentration. The activities of lactase, sucrase and maltase were evaluated in other eight rat's small intestine. The results demonstrated a maltase/sucrase activity rate of 4:1. The gastric retentions of the maltose solution were significantly higher than sucrose solution at 10% and 5% concentration, either 1 and 2 ml/100 g weight. There were no differences between gastric retention at 2.5% concentration neither with 2 nor 1 ml/100 g weight. As an explanation of these results it is proposed that the faster gastric emptying of sucrose solution 10% and 5% in relation with the same concentrations of maltose is due to a probable saturation of sucrase, that when achieved, interrupts the regulation of gastric emptying, determined by the intestinal receptors.
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PMID:[Gastric emptying of sucrose and maltose and levels of respective disaccharidases in the small intestinal mucosa of adult rats]. 787 66

Ninety-six weanling male Wistar rats were fed for four weeks one of two different chows: a normal rat chow containing 55.5% (w/w) starch (control group, N = 48) or a rat chow in which starch was partially replaced by lactose, in such a way that the experimental group (N = 48) received 35.5% (w/w) starch and 20% (w/w) lactose. The gastric emptying of fluid was then studied by measuring the gastric retention of four test meals containing lactose (5% or 10%, w/v) or glucose+galactose (5% or 10%, w/v). Homogenates of the small intestine were assayed for lactase activity. The gastric retention values were obtained 15 min after orogastric infusion of the liquid meals. The median values for gastric retention of the 5% lactose solutions were 37.7% for the control group and 37.0% for the experimental group (P > 0.02). For the 10% lactose solution the median values were 51.2% and 47.9% (P > 0.02) for the control and experimental groups, respectively. However, for the 2.5% glucose +2.5% galactose meal the median gastric retention was lower (P < 0.02) in the group fed a lactose-enriched chow (38.5%) than in the control group (41.6%). For the 5% glucose +5% galactose solution the median values were not statistically different between groups, 65.0% for the control group and 58.8% for the experimental group. The median values of the specific lactase activity in the small intestine homogenate was 0.74 U/g in the control group and 0.91 U/g in the experimental group. These values were not statistically different (P > 0.05). These results suggest that the prolonged ingestion of lactose by young adult rats changes the gastric emptying of a solution containing 5% monosaccharides. This adaptation may reflect the desensitization of intestinal nutrient receptors, possibly by an osmotic effect of lactose present in the chow.
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PMID:Chronic lactose intake modifies the gastric emptying of monosaccharides but not of disaccharides in weanling rats. 929 8