Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human kidney brush border membrane proteins were studied by crossed-immunoelectrophoresis. An antiserum against membrane vesicles was raised in rabbits and used in establishing a reference immunoelectrophoregram with the antigens released by Triton X-100. Among the precipitates observed, the following hydrolases were identified by zymogram staining: Microvillus aminopeptidase (EC 3..4.11.2), gamma-glutamyltransferase (EC 2.3.2.2), maltase (EC3.2.1.20) and trehalase (EC 3.2.1.28). Depletion of the antiserum with sealed, right-side-out vesicles was performed. No precipitates could be seen when the Triton X-100 extract was electrophoresed in a gel containing the depleted antibody. It is therefore suggested that the precipitation of membrane components by the complete antibody is mainly due to externally-located determinants and that the precipitates of the reference pattern correspond to membrane components pointing, at least in part, towards the tubular lumen. Evidence was also noted for a differential removal of antibodies directed against the different antigens. Such an observation could not be explained by the antigen accessibility nor by its amount in the membrane. Parallel crossed-immunoelectrophoresis of Triton X-100 and papain extracts gave rise to an "identity" pattern for only some antigens, particularly for microvillus aminopeptidase and maltase. It is thus strongly suggested that the papain-released form of these enzymes bears nearly all the antigenicity of the whole molecule.
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PMID:Crossed-immunoelectrophoretic study on human renal brush border membrane vesicles. 723 38

Dogs are particularly susceptible to development of glucocorticoid-induced hepatopathy, but the mechanisms are not well understood. We investigated the pathogenesis of glucocorticoid hepatopathy by examining sequential morphologic and biochemical changes in the liver of dogs during steroid administration. Six adult Beagles were given prednisolone acetate (4mg/kg of body weight, once daily for 24 days IM). Serum samples and percutaneous liver biopsy specimens were obtained before the start of the study (treatment day [TD] 0) and at TD 5, 10, 15, and 25. There were significant (P < 0.05) and progressive increases in serum activities of alkaline phosphatase, gamma-glutamyltransferase, and alanine transaminase. Light microscopic changes in liver biopsy specimens included progressive hepatocellular swelling and vacuolation. Electron microscopy revealed glycogen accumulation, peripheral displacement of organelles, and prominent dilatation of bile canaliculi, compared with findings at TD 0. Liver biopsy specimens taken at TD 25 had significantly (P < 0.05) increased activities of the plasma membrane enzymes, alkaline phosphatase and gamma-glutamyltransferase, and 5'-nucleotidase was significantly (P < 0.001) decreased. Subcellular fractionation on reorientating sucrose density gradients revealed high-density peaks of alkaline phosphatase and gamma-glutamyltransferase, compatible with a specific increase in the biliary canalicular component of the enzyme activities. Neutral alpha-glucosidase activity was shifted to the denser fractions, indicative of an increase in the proportion of rough to smooth endoplasmic reticulum and consistent with enhanced synthesis of plasma membrane proteins. There also was evidence for progressive increase in fragility of intracellular organelles, particularly lysosomes. These findings indicate that glucocorticoid hepatopathy in dogs is associated with progressive alterations not only to the plasma membrane, but also to other subcellular organelles.
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PMID:Subcellular pathologic features of glucocorticoid-induced hepatopathy in dogs. 757 58

To examine the postnatal development of equine small intestine, biopsy specimens of jejunal mucosa from 8 ponies, between 6 and 28 weeks old, were subjected to analytical subcellular fractionation and assay of organelle marker enzymes. Fractionation revealed a reduction in the particulate brush border component of beta-galactosidase (lactase) activity between 6 and 28 weeks, and a corresponding increase in soluble activity, although the reduction in mean specific activity was not significant. There also was a decrease in the proportion of brush border to soluble aminopeptidase N activity, a relative loss of brush border gamma-glutamyltransferase activity, and a considerable decrease in the specific activity of alkaline phosphatase throughout the gradient fractions. In contrast, there were marked increases in activities of alpha-glucosidase (maltase) and sucrase in the older ponies, accompanied by considerable changes in the intracellular distribution of particulate alpha-glucosidase activity, which was predominantly associated with endoplasmic reticulum at 6 weeks, whereas the large increase in activity observed by 28 weeks was clearly associated with the brush border. The modal density of brush borders also increased with age, suggestive of an increase in the glycoprotein-to-lipid ratio of the microvillar membrane. In contrast to these brush border changes, there was relatively little alteration in the activities or density distributions of marker enzymes for endoplasmic reticulum, basolateral membranes, mitochondria, or lysosomes. These findings indicate that maturation of equine intestinal epithelium during the first few months of life results in major changes in the properties and enzyme composition of enterocyte brush borders.
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PMID:Subcellular biochemical changes during the development of the small intestine of pony foals. 853 83

Androgens in seminal plasma have been investigated in relation to other markers of the male reproductive system. Testosterone and dihydrotestosterone (DHT) were measured by radioimmunoassay after paper chromatography in 104 semen samples. Concentrations of testosterone and DHT were significantly lower in samples from patients with abnormal sperm characteristics than in men with normozoospermia. Both testosterone and DHT were correlated significantly with sperm concentration (r = 0.40, p < 0.001; r = 0.41, p < 0.001, respectively), motile sperm concentration (r = 0.35, p < 0.01; r = 0.35, p < 0.01) and ATP concentration (r = 0.59, p < 0.001; r = 0.45, p < 0.001). In addition, the total amounts of testosterone and DHT were correlated with total activity of alpha-glucosidase (r = 0.49, p < 0.001; r = 0.58, p < 0.01), and gamma-glutamyltransferase (r = 0.49, p < 0.001; r = 0.48, p < 0.001) in seminal plasma. Transferrin (Tf) concentration in seminal plasma was significantly lower in samples without spermatozoa, and total Tf content was lower in oligozoospermic samples (p < 0.05). Testosterone and DHT were correlated positively with Tf levels in seminal plasma (r = 0.48, p < 0.0001; r = 0.78, p < 0.0001 respectively). Testosterone, DHT and Tf in seminal plasma were higher in the first than in the second fraction of split ejaculates, and DHT, but not testosterone, increased significantly in each of six patients treated with tamoxifen. Testosterone, DHT, and Tf in seminal plasma were not correlated with serum concentrations of LH, FSH, testosterone or prolactin, but the DHT : T ratio in seminal plasma was correlated with serum LH (r = 0.36, p < 0.05). It is concluded that the concentration of androgens in seminal plasma is related predominantly to the activity of the seminiferous epithelium and, to a lesser extent, to the function of the accessory sex glands.
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PMID:Androgens in seminal plasma: markers of the surface epithelium of the male reproductive tract. 856 98

The presence of various cytokines, namely hepatocyte growth factor (HGF), interleukin-1 receptor antagonist (IL-1 RA), and interleukins (IL-1 alpha, IL-6, and IL-8), as well as the production of reactive oxygen species (ROS) was investigated in seminal plasma of fertile and infertile patients in order to evaluate the possible value of measuring these substances for the diagnosis of male accessory gland infection, and to assess the possible relationship between oxidative stress and cytokines during leucocytospermia and male accessory gland infection (MAGI). Our findings indicate that all of the measured cytokines seem to be produced locally as well as by white blood cells (WBC) and that, due to the presence of higher numbers of WBC, accessory gland infection may exert a deleterious effect on sperm quality through the production of ROS and/or of particular cytokines such as IL-1 alpha, IL-1 RA, and IL-8. The most specific marker for a sensitivity of 95% in discriminating between cases with or without MAGI is the measurement of IL-6 in seminal plasma. In the absence of WBC several cytokines are constitutively produced and correlate with sperm concentration (HGF, IL-8), alpha-glucosidase (IL-6), and gamma-glutamyltransferase activity (HGF). The measurement of these cytokines in semen may provide clinically useful information for the diagnosis of male accessory gland infection, as well as in the absence of WBC where it can provide information about certain mechanisms of male reproductive function and dysfunction.
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PMID:The relation between reactive oxygen species and cytokines in andrological patients with or without male accessory gland infection. 901 1

The treatment of Caco-2 cells, a human colon adenocarcinoma cell line that closely resembles normal human small intestinal epithelial cells, with acetaldehyde resulted in significantly decreased activities of brush border enzymes sucrase, maltase, lactase, and gamma-glutamyltransferase; alkaline phosphatase activity was not affected. In the case of sucrase and maltase, the activities were also decreased by a combination of acetaldehyde and ethanol, although ethanol alone markedly increased them. The possibility that intraintestinal acetaldehyde, formed by intestinal microbes, might play a role in some small intestinal enzyme deficiencies observed earlier in alcoholics should therefore be considered. The mechanism by which acetaldehyde alters these enzyme activities remains unclear. The observation that acetaldehyde also disturbed cell polarization, an initial step in the process of differentiation in Caco-2 cells, indicates that acetaldehyde might decrease these enzyme activities by interfering with cell differentiation. Because ethanol and acetaldehyde metabolizing enzymes have not been previously studied from Caco-2 cells, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities were also measured from these cells, and their ALDH isoenzyme pattern was characterized. Like many cancerous cell lines, Caco-2 cells were found to express no ADH. They, however, possessed ALDH activity that was comparable with normal colonic mucosal activity and also expressed the same ALDH classes (ALDHs 1 to 3) than normal human colonic mucosa.
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PMID:Effects of acetaldehyde on brush border enzyme activities in human colon adenocarcinoma cell line Caco-2. 943 18

Measurement of alpha-glucosidase (alpha-GLUC) activity by means of a simple colorimetric test using a commercial kit (EpiScreen; FertiPro, Lotenhulle, Belgium) yielded results that were strongly correlated with the values obtained for the neutral iso-enzyme measured by a fluorimetric reference method (r=0.85, P=0.003, n=13). The former method was characterized by a low intra- and inter-coefficient of variation (6.6 and 4.3% respectively). Vasectomized men with azoospermia (n=27) had a significantly lower alpha-GLUC activity in semen than vasectomized men with residual spermatozoa present (n=11, P < 0.01) and men with azoospermia of primary testicular origin (n=33, P < 0.01). Receiver operating curve (ROC) analysis showed alpha-GLUC measurement to be reasonably accurate in differentiation between cases with obstructive versus testicular azoospermia at criterion value 13.5 U/l (sensitivity=82%, specificity= 70%). In cases with spermatozoa present, alpha-GLUC activity and output per ejaculate were positively correlated with sperm concentration (r=0.53 and 0.38, n=472), linear velocity (r=0.35 and 0.30, n=224), curvilinear velocity (r=0.32 and r=0.29, n=224), semen adenosine triphosphate (r=0.35 and 0.26, n=64), the concentration of 5alpha-dihydrotestosterone (r=0.31 and 0.29, n=74), and gamma-glutamyltransferase activity (r=0.62 and 0.32, n=275) in seminal plasma. The activity of alpha-GLUC was inversely correlated with ROS generation after 12-myristate, 13-acetate phorbol ester stimulation (r=-0.27, n=104), and both alpha-GLUC activity and total output were inversely correlated with the concentration of peroxidase-positive white blood cells among samples with > or =1x10(6)/ml of these cells (r=-0.30 and -0.19, n=165). It is concluded that simple photometric measurement of alpha-GLUC activity in seminal plasma reflects the functional state of the epididymis and may be helpful for the differential diagnosis of certain cases with azoospermia.
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PMID:Seminal plasma alpha-glucosidase activity and male infertility. 957 18

The size, morphology, and mucosal enzyme activity of small intestines in poults were determined from hatch to 12 d of age. Mass and length of the small intestines increased at different rates in the duodenum, jejunum, and ileum and mass increased more than length. Intestinal weight increased more rapidly then other body organs, reaching a peak at about Day 6, and then decreased. Examination of the morphology of the small intestine showed that villus height and area increased several fold in the jejunum and duodenum and less in the ileum over the period examined. Enterocyte size increased slightly in the initial posthatch period. Activities of mucosal enzymes also increased at different rates in the different intestinal segments and sucrase, maltase, and gamma-glutamyltransferase activities per gram of intestine peaked at 2 to 5 d posthatch before decreasing. Regional mucosal intestine activities exhibited a steady increase, which was highly correlated with BW and thus mucosal hydrolysis may be a determining step in digestion. Poult villus size and area were smaller and mucosal enzyme activity was lower than that found in broilers and this may explain the initial slower growth rate in poults.
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PMID:Posthatch development of small intestinal function in the poult. 1005 Oct 34


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