Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Feeding yoghurt or base milk (from which the yoghurt was prepared by fermentation) to rats increased the counts of coliforms in the gut whereas the counts of lactobacilli were reduced by yoghurt but not by the base milk. Lactobacillus bulgaricus survived in the guts of gnotobiotic and conventional rats when yoghurt was fed continuously. Streptococcus thermophilus also survived in gnotobiotic rats but its ability to survive in conventional rats could not be examined. Both organisms failed to colonise the gut when a small inoculum of yoghurt was administered orally to germfree rats maintained on the stock diet. Streptococcus thermophilus but not Lact. bulgaricus grew in the rat diet when tested in vitro. Two enzyme systems (beta-galactosidase and lactase) were studied using, respectively, o-nitrophenyl-beta-D-galactopyranoside (ONPG) and lactose as the test substrates. Enzyme levels estimated with both substrates increased in the gut contents when rats were fed yoghurt but an increase was only found with ONPG in the intestinal mucosa fraction. The bacterial origin of all this increased activity is discussed. The other lactose-containing diets did not affect enzyme activity to the same degree. Feeding yoghurt changed the lactobacillus flora from one which was predominantly heterofermentative (Lact. reuteri ) to one which was predominantly homofermentative (Lact. salivarius).
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PMID:The effect of yoghurt on some components of the gut microflora and on the metabolism of lactose in the rat. 642 70

The addition of microbial beta-galactosidases directly to milk at mealtime represents a potential "enzyme replacement therapy" for primary lactase deficiency. We used the hydrogen breath test as the index of incomplete carbohydrate absorption to assess the efficacy of two enzymes--one from yeast, Kluyveromyces lactis (LactAid), and the other from the fungus Aspergillus niger (Lactase N)--to assist in the hydrolysis of 18 g of lactose in 360 ml (12 oz) of whole milk when consumed by an adult lactose malabsorber. Graded amounts of Lactase N produced, at best, a 53% relative reduction in breath hydrogen excretion, whereas quantitative elimination of excess hydrogen excretion was produced by 1 and 1.5 g of LactAid. A double-blind, controlled, crossover trial was subsequently performed in 50 healthy, unselected Mexican adults, to whom 360 ml of cow's milk was presented in the three forms in a randomized order: intact milk, prehydrolyzed milk, and milk to which 1 g of LactAid was added immediately before consumption. Among the 25 subjects with incomplete carbohydrate absorption with intact milk, adding enzyme 5-min before consumption produced a 62% reduction in breath hydrogen excretion, and symptoms of intolerance were significantly reduced. The feasibility of effective enzyme replacement therapy with a beta-galactosidase from K. lactis is demonstrated.
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PMID:Enzyme replacement therapy for primary adult lactase deficiency. Effective reduction of lactose malabsorption and milk intolerance by direct addition of beta-galactosidase to milk at mealtime. 643 67

Comparisons between papain- and Triton X-100-solubilized lactase (EC 3.2.1.23) were made in terms of elution from various chromatographic columns and by molecular weight determinations. Using these techniques, no major differences could be detected. Since papain-solubilized enzyme would be cleaved at the hydrophilic-hydrophobic interface and detergent would release the amphipathic enzyme, the lack of detectable differences between purified lactase solubilized by the two agents suggests the existence of a relatively small anchoring moiety in rats when compared to that suggested in previous studies for adult humans.
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PMID:Comparison of detergent versus protease solubilized rat intestinal lactase. 643 55

The aim of this study was to determine the extent to which the postnatal maturation of intestinal hydrolases in the rat is dependent on the developmental rise of circulating corticosterone that occurs at the end of the 2nd wk of life. Pups were adrenalectomized (adX) on day 9 (i.e., before the developmental surge of corticosterone begins) and were killed on days 17, 20, 23, and 26. Serum corticosterone was measured to eliminate any incompletely adX animals. The rates of the developmental increases of sucrase and maltase activities and the developmental decreases of lactase and acid beta-galactosidase activities were depressed in adX pups aged 23 days and younger as compared with sham-operated controls. Administration of corticosterone (10 micrograms X g body wt-1 X day-1) to adX pups restored the developmental changes of these enzyme activities to rates equal to or greater than those in the sham-operated pups. By 26 days of age, all four enzyme activities of adX pups had reached their normal ontogenic plateau. We conclude that adrenal corticosteroids are potent determinants of the rate of developmental changes of intestinal hydrolases but that these hormones are not necessary for enzymes to eventually reach adult activities.
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PMID:Enzymic development of the small intestine: are glucocorticoids necessary? 674 20

The weanling process is characterized by the transition from a liquid diet poor in iron (rat milk) to a solid diet high in iron (chow pellets). To examine the effects of iron content of the weanling diet on terminal maturation of rat small intestine, suckling pups, nursed by iron-sufficient mothers, were weaned by day 16 onto a solid basal diet that was either deficient [low-iron diet (LID): 0.5 mg iron/100 g solid] or high [high-iron diet (HID) controls: 30 mg iron/100 g solid] in iron. The animals were studied during or at the end of the 4th postnatal wk. By day 17 rats weaned onto the LID exhibited an initial rise in jejunal sucrase activity as did their controls, but the activity plateau of the enzyme was reduced to a level 60% of the controls. On day 28 iron-deprived rats were anemic and showed significant decreases (P less than 0.01 compared with HID rats) in the activity of jejunal sucrase (-57%), neutral lactase (-83%), and maltase (-46%), whereas villus height, crypt depth, mucosal mass parameters, ileal acid beta-galactosidase activity, mucosal protein, and DNA synthesis rates were equivalent in LID and HID groups. The concentration of the secretory component, a glycoprotein synthesized by the intestinal crypt cell, was markedly depressed (P less than 0.01 vs. controls) in the jejunum (-54%) and ileum (-79%) of iron-deprived rats. When D-[1-14C]glucosamine was injected intraperitoneally, incorporation of the label into jejunal and ileal brush-border proteins was two to three times lower for iron-deficient rats than for controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Role of dietary iron in maturation of rat small intestine at weaning. 674 22

The complex between lactase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) and phlorizin hydrolase (glycosyl-N-acylsphingosine glycohydrolase, EC 3.2.1.62) has been purified from the proximal and distal regions of the small intestine of suckling rats. The two enzymes behaved differently on DEAE-cellulose ion-exchange chromatography and during electrophoresis in the presence and absence of sodium dodecyl sulphate (SDS), but they have very similar cyanoge bromide cleavage patterns. Kinetic studies on the proximal and distal enzymes showed the same pH optimum of 6.0 and the same heat stability at 45 degrees C, but a small difference in Km. Treatment of both enzymes with fucosidase, mannosidase or N-acetylhexosaminidase did not affect enzymic activity or electrophoretic mobility. Neuraminidase digestion abolished the electrophoretic differences and gave two active enzymes with similar isoelectric points.
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PMID:Isolation and characterization of the proximal and distal forms of lactase-phlorizin hydrolase from the small intestine of the suckling rat. 677 1

The adaptability of intestinal microvillar alpha-disaccharidases to the variation of alpha-saccharide content in the diets is well established, but the influence of these sugars on the activity of microvillar lactase (neutral beta-galactosidase) has heretofore been considered negligible or non-existing. In two experiments rats were fed isocaloric diets where the carbohydrate (starch or sucrose) content versus fat content was varied. (High carbohydrate diets: 71% of calories as carbohydrate and 5% of calories as fat; low carbohydrate diets: 6 and 73% calories, respectively). Experiment 1: male and female rats had access to experimental diets only from day 12 postnatally and were killed at age 56 days. Experiment 2: male rats were fed experimental diets starting on day 73 postnatally and killed 3, 7, 14 and 28 days later. Rats fed the high carbohydrate diets exhibited a significant increase in activity (specific and total per segment) of lactase in all three intestinal segments compared to rats fed the low carbohydrate diets. Changes in the activity of sucrase and maltase paralleled those of lactase activity. These experiments have thus demonstrated clearly the influence of variation in alpha-saccharide content in the diet upon lactase activity. Further experiments are needed to determine the active principle of this dietary adaptation.
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PMID:Increased activity of rat intestinal lactase due to increased intake of alpha-saccharides (starch, sucrose) in isocaloric diets. 678 80

Although it is generally accepted that lactase (beta-D-galactosidase, EC 3.2.1.23) activity is not influenced by intake of saccharides containing alpha-linkages, an effect of these carbohydrates on lactase activity was never thoroughly investigated. Activity of lactase and sucrose alpha-D-glucohydrolase, EC 3.2.1 48) was determined in proximal, middle and distal thirds of the jejunoileum of female, 12-week-old rats, fed for 2 weeks a low-starch (5 cal%), high-fat (73%) diet, and in rats, that after this introduction period were fed for 1, 2 and 3 days, an isocaloric middle-starch (40%), middle-fat (36%) diet or an isocaloric high-starch (70%), low-fat (7%) diet. During the entire experimental period, the body weight changes, food intake and the amount of protein per segment were practically the same in all three dietary groups. In all intestinal segments, increased intake of starch was followed by an increase of lactase and sucroase activity (both expressed as per tissue protein or per intestinal segment ) within the first day. The increase continued during the second day and leveled off during the third day. A highly significant linear correlation was found between the search content of the diets and the lactase activity in all three segments. A highly significant correlation was also established in all three segments between sucrase and lactase activities. These studies thus demonstrated a dose- and time-dependency between the intake of starch (a carbohydrate containing only alpha-linkages) and the activity of lactase, a neutral beta-galactosidase in adult rats.
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PMID:Time- and dose-dependency of intestinal lactase activity in adult rat on starch intake. 678 85

Jejunal sucrase is known to display glucocorticoid responsiveness from birth through day 17 but not beyond that age. The aim of the current study was to determine whether this abrupt loss of responsiveness was shared by maltase, lactase, and acid beta-galactosidase. Glucocorticoid concentrations were manipulated by both adrenalectomy (ADX) and by administration of cortisone acetate (CA). Surgery or treatment was performed on each day from 16--22 days of age. Maltase activity was reduced by ADX at day 18 and earlier and was increased by CA at days 16 and 17. There were no effects at later ages. Acid beta-galactosidase was increased by ADX only at day 18 and earlier and was decreased by CA only at day 16. Lactase activity was increased by ADX at all ages up to and including day 20 but was reduced by CA only at days 16 and 17. Thus, we conclude that loss of glucocorticoid responsiveness at a relatively early stage of development is a common feature of both brush-border and lysosomal enzymes of the small intestine.
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PMID:Coordinate loss of glucocorticoid responsiveness by intestinal enzymes during postnatal development. 680 95

1. The levels of the brush-border enzymes sucrase (sucrose glucohydrolase, EC 3.2.1.48), isomaltase (oligo-1,6-glucosidase, EC 3.2.1.10), maltases 2 and 3 (glucoamylase, EC 3.2.1.3), lactase (beta-galactosidase, EC 3.2.1.23) and trehalase (EC 3.2.1.28) and adsorbed pancreatic alpha-amylase (EC 3.2.1.1) have been measured at twenty-one positions along the small intestines of eighty-four pigs of different ages ranging from 3 weeks to 4.5 years. The state of dilation of the intestine at the sampling points was noted. 2. The levels of sucrase and isomaltase increased with age throughout the age-range studied. Trehalase and the glucoamylases increased with age up to 200--300 d of age. Lactase decreased with age over the whole age range. 3. For the pigs above 10 weeks of age, the distribution pattern of the brush-border enzymes along the intestine did not change with age. Each enzyme had a characteristic distribution curve, with low values at the proximal and distal ends and a peak which was proximal in the instance of lactase and trehalase and approximately mid-way along the gut with sucrase, isomaltase and the glucoamylases. 4. The pattern of distribution of the brush-border enzymes altered with age in the piglets, but approached the adult pattern by 8 weeks. 5. Piglets weaned at 3 weeks had higher levels of sucrase, isomaltase and glucoamylases at 5 weeks than piglets left on the sow. At 8 weeks of age the piglets weaned at 3 weeks still had higher sucrase and isomaltase levels than those on the sow. 6. There was a very close correlation between the sucrase and isomaltase levels, and between the maltase 2 and maltase 3 levels in all the samples, and a fairly close correlation between all these four enzymes. 7. The level of alpha-amylase increased with age but showed no regular distribution pattern, its irregular fluctuations being related to the presence or absence of dilation of the intestine at the time of slaughter rather than to the position along the intestine.
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PMID:The level of distribution of carbohydrases in the small intestine mucosa of pigs from 3 weeks of age to maturity. 696 56


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