Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.26 (invertase)
4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Graded levels of hydrocortisone 21-acetate (HYD) (0, 18, 16 and 24 mg/kg BW) were injected into nursing piglets every other day (Exp. 1) or 24 mg of HYD/kg BW was administered 0, 2, 4 or 6 times during the treatment period (12 d) with equal time (6 d, 3 d or 2 d) between subsequent injections (Exp. 2). Adrenocorticotropic hormone (ACTH) was injected to provide 0, 5, 10 or 15 IU/kg BW (Exp. 3), or 15 IU ACTH/kg BW was injected 0, 1, 2 or 3 times (Exp. 4). The injection treatment periods were from d 14 to d 26 postpartum. Pancreatic and intestinal amylase activity was maximized by the highest dosage of HYD (24 mg) and ACTH (15 IU) when given at 2- or 4-d intervals, respectively (P less than .10). However, four injections of HYD administered 3 d apart optimized the activity of this enzyme in Exp. 2 (P less than .05). Intestinal sucrase and maltase were unresponsive to ACTH regardless of dosage or injection frequency (P greater than .10). The response of these two enzymes to HYD was inconsistent. Maltase activity was elevated (P less than .10) by the two most frequent injection treatments, and sucrase activity was simultaneously depressed. Lactase activity tended (P less than .15) to be depressed by the highest treatment level in all four experiments. Both dosage and frequency methods of increasing HYD administration resulted in hepatic and pancreatic hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Response of digestive carbohydrases and growth to graded doses and administration frequency of hydrocortisone and adrenocorticotropic hormone in nursing piglets. 255 56

Two experiments were conducted that demonstrated that a single injection of hydrocortisone 21-acetate (HYD, 25 mg/kg BW) administered to 6-d-old nursing piglets resulted in a twofold elevation (P less than .02) of pancreatic amylase within 2 d; activity was unaffected by an injection of 15 IU adrenocorticotropic hormone (ACTH)/kg BW (P greater than .20). Intestinal sucrase and maltase activity tended to be elevated (P less than .20) 2 and 4 d postinjection with HYD but returned to normal (uninjected) levels by 14 d of age. The normal decline of intestinal lactase activity was delayed by at least 4 d in response to both hormones (P less than .10). Organ weights were not affected by either hormone. In a separate experiment, postweaning mortality was reduced (12 vs 27%) and growth rate was substantially improved by administration of HYD to piglets 4 and 2 d prior to weaning at 14 d of age. Hydrocortisone resulted in a faster rate of gain the 1st wk postweaning for pigs weaned at 21 or 28 d. Subsequent gain by control and HYD piglets weaned on d 21 was similar, but HYD subsequently impaired growth rate of piglets weaned at 28 d of age. Growth rates of control and ACTH piglets were similar at each postweaning period regardless of weaning age (weaning age [lin.] x week postweaning [quad.] x treatment, P less than .07). This differential treatment response of daily gain may be due in part to effects on feed intake (weaning age [lin.] x week postweaning [lin.] x treatment, P less than .10). We conclude that a single injection of HYD to 6-d-old piglets precociously induces pancreatic amylase and that the sensitivity of piglets to HYD is age-dependent.
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PMID:Temporal changes in carbohydrate digestive capacity and growth rate of piglets in response to glucocorticoid administration and weaning age. 255 57

Raffinose hydrolysis was studied in Saccharomyces rouxii. The responsible enzyme was identified as a beta-fructofuranosidase (EC 3.2.1.26), which has a pH optimum of 5.5 and a K(m) of 83 mM for raffinose. This enzyme was cryptic in cells from a 3-day culture. A 2-min treatment with 0.1 volume of ethyl acetate in sodium acetate buffer (pH 6) gave complete expression of the enzyme, which was still retained by the cell. Ghosts were prepared by modifying membrane structure with small basic proteins in distilled water, and after washing they showed the full complement of enzymatic activity. The enzyme remained cryptic in osmotically protected spheroplasts; however, after lysis (by dilution) release, as well as expression, was effected. Mechanical disruption of fresh cells revealed and released all of the enzyme. Cells in early stationary phase had all of their beta-fructofuranosidase in a cryptic state. Aging yielded fractional expression of activity; initially this was proportional to cell death, but later the degree of expression exceeded the death rate. Media from aged cultures or cell-free extracts of aged cells were not effective in revealing the cryptic enzyme of younger cells. S. rouxii beta-fructofuranosidase has a different autolytic-release pattern from its counterpart in S. cerevisiae. Also, high concentrations of glucose do not repress the S. rouxii enzyme. The beta-fructofuranosidase in young cells of S. rouxii must be enclosed by the protoplasmic membrane or a special vesicular structure. This system was compared with other Saccharomyces species in connection with the translocation of enzymes across the protoplasmic membrane.
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PMID:Expression of cryptic beta-fructofuranosidase in Saccharomyces rouxii. 445 87

1. Cortisone administration to suckling rats leads prematurely to induction of enzymes of the intestinal microvillus plasma membrane and lengthening of the intestinal microvilli. To investigate the membrane changes that might be involved, a method for the isolation of a fraction enriched with microvillus plasma membrane was developed in suckling rats. Plasma-membrane fractions were compared from 13-day-old control rats and from 13-day-old rats given cortisol acetate by subcutaneous injection for 3 days. 2. After cortisol injection, the activity of maltase, trehalase, sucrase and leucyl beta-naphthylamidase increased markedly, and to the same extent, in intestinal homogenates and plasma-membrane preparations. Purification, and recovery of five marker enzymes with respect to homogenate activity, and recovery of protein, were similar for both membrane preparations, particularly after correction for non-membrane activity, which was high in suckling rats and affected by cortisol. 3. In material released from the plasma membrane by digestion with papain, maltase protein was increased after cortisol injection at least as much as maltase activity. Sucrase activity increased at least 200-fold, and this increase was associated with the appearance of a new sucrase band on polyacrylamide-gel electrophoresis. 4. Sodium dodecyl sulphate electrophoresis of plasma-membrane proteins revealed at least four additional macromolecules after cortisol injection. Concurrently several proteins disappeared from the plasma membrane. The added proteins appeared in the main to be removed from the plasma membrane by papain, whereas the deleted proteins were in the papain-resistant fraction. 5. Enzymic stimulation induced by cortisol acetate in the suckling-rat plasma membrane therefore appears to involve the addition of new proteins, rather than activation of proteins in situ. Deletion of proteins from the membrane during induction of hydrolytic enzymes may reflect other phenomena such as protein reorganization associated with the change in microvillus shape.
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PMID:Isolation of microvillus plasma membranes from suckling-rat intestine. The influence of premature induction of digestive enzymes by injection of cortisol acetate. 446 84

The effects of medroxyprogesterone acetate (MPA) on the digestive and absorptive functions of the small intestinal epithelium have been investigated in female albino rats. The transport of sodium-dependent glucose was significantly enhanced while sodium-independent transport remained unaltered in drug-treated animals. The uptake of amino-acids was also considerably increased, while Ca++ uptake decreased significantly on administration of the drug at a dose of 35 mg/kg body weight once a week for 1 month. Kinetic studies of glucose transport in the presence of sodium ions revealed that MPA treatment affected the rate of uptake of glucose by elevating Vmax, but the Km value remained the same in treated and untreated animals. The administration of the drug also led to significant augmentation in the activities of the brush border enzymes, disaccharidases, and to an insignificant decrease in alkaline phosphatase. The activities of leucine aminopeptidase did not show any change. The enhancement in sucrase activity might be due to induction of the enzyme because only Vmax was elevated in treated animals. As concerns cellular enzymes, lactate dehydrogenase activity was significantly depressed. This study suggests that MPA also exerts glucocorticoid-like effects on the intestinal tissue.
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PMID:Effect of medroxyprogesterone acetate on the digestive and absorptive functions of rat intestine. 623 Dec 5

To study the effect of corticosteroids on postnatal maturation of Na+ transport in the small intestine, we studied 10-12-day-old suckling rabbits after they had received cortisone acetate, 20 mg/kg SC on days 3, 4, and 5 of life. When killed, the cortisone-injected animals weighed significantly less than saline-injected controls. In jejunal villus enterocytes isolated from this cortisone-treated group, the specific activities of sucrase and Na+-K+-ATPase were significantly greater than those in control enterocytes. Studied in Using chambers, a significant electrical and ion-flux response to glucose was observed in the jejunal epithelium of the treated group, but not in controls. We conclude that exogenous cortisone, administered early in life, can stimulate the precocious development not only of certain epithelial enzymes but also glucose-facilitated Na+ transport in the jejunum of the rabbit.
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PMID:Effect of cortisone on postnatal development of ion transport in rabbit small intestine. 627 34

The effect of a single oral dose of pp'DDT (100 mg/kg body wt.) has been studied on the intestinal uptake of certain nutrients and on brush border enzymes in rats. Intestinal uptake of leucine, and phenylalanine was considerably increased but there was no change in the absorption of glucose and alanine in DDT fed rats, compared to controls. The activities of brush border sucrase, alkaline phosphatase and Na+, K+-ATPase were significantly depressed in pesticide treated animals, but leucine aminopeptidase levels remained unaffected under these conditions. Analysis of the chemical composition of the microvillus membranes revealed a considerable enhancement in total lipids, phospholipids and triglyceride contents of the membranes in DDT exposed rats, but membrane protein, sialic acid and cholesterol fractions did not record any change. 1-14C-acetate incorporation into various lipid classes was studied to explain the observed increase in membrane lipids in DDT exposed animals.
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PMID:Effect of a single oral dose of pp'DDT on the absorption of nutrients in vitro and on brush border enzymes in rat intestine. 627 79

A temperature-sensitive mutant of Saccharomyces cerevisiae (DAM303) is described that exhibits an early defect in lipid biosynthesis at the restrictive growth temperature, 37 degrees C. This strain rapidly lost viability after 1 h of incubation at 37 degrees C, and this was accompanied by a significantly reduced incorporation of 32Pi into cellular lipid and an accumulation of [1-14C]acetate into the free fatty acid fraction. The temperature-sensitive DAM303 mutation failed to complement the sec13 mutation described by Novick et al. (Cell 21:205-215, 1980), and from analysis of invertase secretion in the temperature-sensitive DAM303 strain, it is clear that the loss of invertase secretion in the mutant occurs after the loss of phospholipid synthesis. Although the precise nature of the temperature-sensitive lesion in the DAM303 strain has still to be identified, the results from the study of this mutant indicate that a defect in lipid biosynthesis can be correlated with subsequent alterations in extracellular protein secretion and loss of other macromolecular functions including DNA, RNA, and protein syntheses. From studies of this mutant, two procedures of enriching for other temperature-sensitive mutants with defects in lipid biosynthesis have emerged: inositol overproduction and screening for increased buoyant densities.
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PMID:Temperature-sensitive Saccharomyces cerevisiae mutant defective in lipid biosynthesis. 635 78

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

Two monoclonal antibodies, designated BB 3/34/12 and BB 5/8/40/90, have been produced to rat intestinal sucrase/isomaltase (SI) by the hybridoma technique using microvillus membranes as antigen. The BB 3/34/12 antibody was shown to be specific for the sucrase subunit. These antibodies provided new information regarding the biosynthesis and postnatal development of SI. In rat intestinal fetal transplants, SI was found exclusively in the form of an enzymatically active high molecular weight precursor, confirming our previous observations concerning the role of luminal proteases for the processing of SI in the microvillus membrane. The SI precursor, purified by affinity chromatography using the BB 3/34/12 antibody, had both sucrase and isomaltase activities, suggesting that a single precursor protein generates both sucrase and isomaltase subunits by proteolytic cleavage. The initial appearance of SI during normal postnatal development in the rat intestine was found to be confined to the cells present at the base of the villi. The same localization was observed after precocious induction of SI by cortisone acetate. In both cases, no immunofluorescence was observed in the crypts, suggesting that only the differentiated enterocyte is capable of synthesizing this enzyme. Even at the earliest times of appearance, newly synthesized SI was found almost completely split into its subunits, suggesting that the protease(s) responsible for the processing of the precursor in the microvillus membrane develop(s) in parallel with SI or earlier.
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PMID:Monoclonal antibodies to sucrase/isomaltase: probes for the study of postnatal development and biogenesis of the intestinal microvillus membrane. 693 73


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