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:3.2.1.20 (alpha-glucosidase)
4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nonylphenol, an environmental contaminant, has been shown to induce reproductive abnormalities in male rats. The nature and mechanism of action of nonylphenol on the epididymal sperm has not been elucidated. In the present study we have sought to investigate whether administration of nonylphenol induces oxidative stress in rat epididymal sperm. Nonylphenol was administered orally to male rats at 1, 10 and 100 microg/kg body weight per day for 45 days. Twenty-four hours after the last treatment, rats were weighed and killed using anaesthetic ether. The body weight of the animals treated with nonylphenol did not show any significant change. The weights of the testes and epididymides decreased significantly whereas the weights of seminal vesicles and ventral prostate remained unchanged at all doses of nonylphenol in treated rats. Epididymal sperm were collected by cutting the epididymides into small pieces in Ham's F-12 medium at 32 degrees C. Administration of nonylphenol decreased the epididymal sperm counts in a dose-dependent manner. The activities of antioxidant enzymes superoxide dismutase, catalase, glutathione reductase and glutathione peroxidase decreased significantly while the levels of H(2)O(2) generation and lipid peroxidation increased significantly in the animals treated with nonylphenol when expressed in terms of milligram protein and milligram DNA. The activity of alpha-glucosidase, a negative control against antioxidant enzymes, in the sperm of nonylphenol-treated rats did not show any significant change at any of the doses. The results suggest that graded doses of nonylphenol elicit depletion of antioxidant defence system in sperm, indicating nonylphenol-induced oxidative stress in the epididymal sperm of rats.
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PMID:Effect of nonylphenol on the antioxidant system in epididymal sperm of rats. 1224 13

The authors carried out a retrospective study of 162 cases of male infertility explored in a hospital unit in Lyon, France. Assays of 1 -alpha-1,4-glucosidase (epididymal function marker) backed up by clinical findings were used to select 3 types of epididymal malfunction. 1) There was complete obliteration of the epididymal duct, resulting in azoospermia. This diagnosis was based on both testicular biopsy findings, demonstrating unimpaired spermatogenesis and on the dramatically reduced level of assayed activity ( 40 mIU/ejaculation), as well as on clinical findings. 2) There was anamalous epididymal function combined with moderate oligoasthenozoospermia or normospermia. In these cases, low levels of assayed activity do not parallel fairly high sperm counts (between 20-30 million spermatozoal/ml). 3) There were those cases which were difficult to interpret and which involved severe oligoasthenozoospermia ( 5 million/ml) and reduced level of epididymal marker, suggesting partial blockage of the epididymis due to a focus of infection. Varicoceles were found more frequently among the European population, whereas a history of genital infection was more frequent among the North African population. However, when the various types of abnormality in the spermatogram were related to patient history and epididymal abnormality, no differences were found between the 2 populations. (author's modified)
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PMID:[Comparative study of epididymal disorders in two populations of male patients consulting for infertility: one from the Maghreb region of North Africa and the other of European origin]. 1231 60

A history of urogenital inflammation occurs in 5-12% of men attending infertility clinics. Usually, infection has a detrimental effect on sperm quality by reducing concentration and motility, and possibly affecting the number of morphological normal spermatozoa. In addition, infection may be the source of auto-antibodies against spermatozoa, found in about 8% of the infertile male population. In contrast to the situation in women, there is no clear evidence that male accessory gland infections can result in epididymal blockage or vassal obstruction, with the exception of genital tuberculosis. Although Chlamydia trachomatis is a well-documented source of chronic prostatitis, the infection does not seem to cause obstruction of the reproductive tract, as it does in women. If male urogenital infection causes obstruction it is most likely located at the level of the ejaculatory ducts. Chronic prostatitis has been proved to cause scarring of the prostatic and ejaculatory ducts, resulting in low seminal volume with low fructose and alpha-glucosidase. Many of these men present with severe oligozoospermia or azoospermia, normal size testis and normal gonadotrophins. We performed an excisional testicular biopsy in all men presenting with <1 million spermatozoa per millilitre and found that 39 of 78 (50%) had a normal spermatogenesis. A history of male accessory genital infection was found in 12% of the men and 10% had abnormalities found on transrectal ultrasound of the prostate (like oedema, dilatation of the seminal vesicles and ejaculatory ducts) intraprostatic calcifications and dilatation of the periprostatic venous plexus. Ejaculatory duct obstruction is a common cause of male infertility and infections are present in at least 22-50% of these men. Transurethral resection of the ejaculatory ducts may result in a significant improvement of the sperm quality and in spontaneous pregnancies in up to 25% of the couples. In case of failure sperm aspiration from the epididymis and intracytoplasmic sperm injection is the treatment of choice.
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PMID:Inflammatory-associated obstructions of the male reproductive tract. 1453 64

A partially purified flavonoid-rich extract was prepared from the seed of Vitex negundo. The effect of this extract on the reproductive system of male rats was investigated at four different concentrations. All the major accessory sex organs shed weight when the preparation was administered at doses of >or=15 mg/rat/day after 15 days of treatment. The drop in weight was also reflected in disturbed tissue biochemistry. Secretory products such as citric acid in the prostate, fructose in seminal vesicles and epididymal alpha-glucosidase activity, indices of accessory sex organ function in males, diminished. Microscopic examination of the sperm derived from the cauda epididymides of treated animals showed only a marginal change in vitality. However, sperm numbers dwindled and slackness in their motility was observed, factors that may impede fertility. Toxicity testing in blood did not point to distress in any of the vital organs. Taken together, it is inferred that the seed extracts of V. negundo interfere with male reproductive function without producing adverse toxicity in other vital organs.
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PMID:Reproduction in male rats is vulnerable to treatment with the flavonoid-rich seed extracts of Vitex negundo. 1475 Jan 93

The expression of alpha-1,4-glucosidase activity was fluorometrically and electrophoretically assessed in the epididymal fluid and seminal plasma of stallions. alpha-Glucosidase specific activity in the epididymis increased significantly from the proximal caput to the cauda. Stallion epididymal glucosidase maintained activity in a wide range of pH, with two distinct peaks (around pH 4.0 and 6.0, respectively). Enzyme activities at different pH, inhibition assays with sodium dodecyl sulfate (SDS) and maltotriose (MTT, selective inhibitors of alpha-glucosidases "acidic" and "neutral" isoforms, described in other tissues) and the electrophoretic analysis in native and native/SDS-PAGE conditions, indicated that stallion epididymal glucosidase was due to two catalytically active forms. These forms, analyzed by non-denaturing electrophoresis, exhibited different electrophoretic mobility and molecular weight. Samples from the proximal caput of the epididymis were rich in Form II or "neutral" form, whereas the "acid" or Form I seemed to be predominate in the cauda epididymal region. At physiological pH, Form II was predominant in the seminal plasma. The physiological role(s) of these forms is uncertain, but based on their ability to hydrolyze glucosidic linkage, they probably are involved in degradation/modifications of epididymal fluid and/or spermatozoa glycoconjugates, thereby participating in plasma membrane remodeling associated with sperm maturation.
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PMID:Identification and partial characterization of alpha-1,4-glucosidase activity in equine epididymal fluid. 1503 84

Alpha-glucosidase activity (EC.3.2.1.20) is present in human seminal plasma, and the neutral form of the enzyme originates almost exclusively from the epididymis. In this study, the specific immunocytochemical location of alpha-glucosidase in the human epididymis was evaluated using a polyclonal antibody. Furthermore, a spectrophotometric assay was employed to assess epididymal obstruction in infertile patients. The enzymatic activity of alpha-glucosidase free of prostate isoform (AGFPI) was determined spectrophotometrically at 405 nm. According to AGFPI activity, patients with leucocytospermia, oligozoospermia and azoospermia were recorded as having normal values or low values indicating epididymal obstruction. Specific immunochemistry staining was demonstrated in the cytoplasmic cells at the epithelial level, in the transition area and in the efferent ducts. The values of the three groups and the control were as follows (mean +/- SEM): normozoospermia (control): 20.2 +/- 1.4 mU ml(-1); azoospermia: normal value: 17.6 +/- 2.2 mU ml(-1), low value: 7.4 +/- 1.8 mU ml(-1); oligozoospermia: normal value: 22.3 +/- 2.5 mU ml(-1), low value: 7.3 +/- 0.7 mU ml(-1); leucocytospermia: increase value: 38.9 +/- 3.7 mU ml(-1), low value: 11.1 +/-1.3 mU ml(-1). This study suggests that determination of alpha-glucosidase might be helpful to evaluate functions of the epididymis and particularly to exclude epididymal obstruction.
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PMID:Alpha-glucosidase in the human epididymis: topographic distribution and clinical application. 1545 51

Although there are contradictory reports, the biochemical evaluation of the seminal activity of neutral alpha-glucosidase (NAG) has repeatedly been described as an important parameter to test epididymal patency and is recommended by the WHO. Because, for a number of diagnostic parameters, seasonal variations have been described even in the human, it was the aim of this study to investigate possible circannual changes of NAG. This is an important aspect of andrological diagnosis, as seasonal changes of specific diagnostic parameters might have an impact on the accuracy and predictive power of these parameters, which in turn might have an effect on the therapeutic concept for the patients. In a total of 473 patients, sperm concentration, volume of the ejaculate, total motility, progressive motility, pH value, number of peroxidase-positive cells, concentration of fructose, and NAG as functional markers of the seminal vesicles and the epididymis, respectively, were analyzed according to standard procedures. Seminal activity of NAG was significantly correlated with the sperm concentration (P < .0001), ejaculate volume (P < .0001), and the pH (P = .0025). Moreover, significant (P = .0008) seasonal changes in the activity of seminal NAG with the maximum in spring (76.87 mU/ejaculate) and the minimum in autumn (58.55 mU/ejaculate) were found. The incidence of low-ranged activity of the enzyme was 9.2% in spring, while it was 20.3% in autumn. Thus, our data clearly demonstrate circannual changes of the seminal activity of neutral alpha-glucosidase. This in turn has clinical impact as the predictive power of the test system changes throughout the year.
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PMID:Seasonal changes of neutral alpha-glucosidase activity in human semen. 1640 75

Androgens, including 5alpha-dihydrotestosterone (DHT), are known to play a role for spermatogenesis and accessory sex gland function. The enzyme 5alpha-reductase (SRD5A) catalyses the conversion of testosterone to DHT. Our objective was to investigate whether polymorphisms in the SRD5A2 gene influence semen parameters in the general population. DNA from 182 Swedish military conscripts was examined for the A49T, V89L, and R227Q polymorphisms in the SRD5A type 2 gene. Ejaculates were analysed according to WHO guidelines. In addition, sperm motility was assessed using computer-aided sperm analysis (CASA). Seminal markers of epididymal (neutral alpha-glucosidase), prostatic (prostate specific-antigen and zinc), and seminal vesicles function (fructose) were measured. The A49TT-allele was associated with significantly higher sperm concentration compared with the wild type A-allele (mean: 102 x 10(6)/mL vs. 57 x 10(6)/mL, p = 0.02). The V89LV-genotype was correlated with significantly higher proportion progressive motile spermatozoa compared with the L-variant (mean: 55% vs. 48%, p = 0.04). The same trend was found regarding the CASA motile spermatozoa (mean: 52% vs. 41%, p = 0.02). No association between any of the polymorphisms and biochemical markers was found. SRD5A2 gene variants were associated with sperm concentration and motility, but not with epididymal and accessory sex gland markers. This effect on sperm parameters might therefore be exerted via a direct effect of DHT on spermatogenesis.
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PMID:Significant impact of 5alpha-reductase type 2 polymorphisms on sperm concentration and motility. 1648 6

We wanted to investigate the origin of seminal plasma albumin and its relation to the male reproductive parameters. Semen samples from 916 men, under infertility assessment, were analysed according to guidelines of the World Health Organization. Seminal plasma constituents, i.e. albumin, markers of the epididymal (neutral alpha-glucosidase, NAG), prostatic (prostate-specific antigen, PSA, and zinc) and seminal vesicle function (fructose), as well as levels of reproductive hormones in plasma were measured. The sperm chromatin structure assay (SCSA) was applied on 267 of the 916 samples. A negative correlation was seen for seminal albumin and plasma follicle-stimulating hormone (r=-0.1, P=0.02) and a positive correlation for seminal albumin and serum inhibin B (r=0.2, P=0.004). Albumin exhibited positive correlations with the epididymal marker, NAG (r=0.5, P<0.001) and with the prostatic markers, PSA and zinc (r=0.1, P=0.001; r=0.2, P<0.001 respectively) as well as with age (r=0.2, P<0.001). A negative significant association was seen for seminal albumin and semen volume (beta=-0.60; 95% CI -0.80 to -0.30). The opposite trend was found regarding sperm concentration (beta=0.34; 95% CI 0.30-0.40), total sperm count (beta=0.30; 95% CI 0.20-0.40), and percentage morphologically normal spermatozoa (beta=0.70; 95% CI 0.10-1.0). No association was found between albumin and sperm motility, SCSA parameters, or fructose, the marker of seminal vesicles. Our results suggest testicular, epididymal and prostatic origin of seminal plasma albumin, in addition to the contribution from blood. This is the first study to demonstrate an association between seminal plasma albumin and sperm morphology. Further studies are needed to elucidate the role of seminal albumin in sperm morphology.
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PMID:Seminal plasma albumin: origin and relation to the male reproductive parameters. 1743 Apr 25

Neutral alpha-glucosidase (NAG) activity is considered a functional epididymal marker in several species. Unlike the rat, no NAG activity has been detected in mice. The aims of the present study were to evaluate NAG secretory activity (the supernatant of the incubated tissue) in mouse epididymis and to determine whether it could be used as a functional epididymal marker. Epididymides (whole or in parts) were incubated in the presence or absence of testosterone (10(-5) m) and secretory NAG activity was compared with known positive controls. Furthermore, we compared enzyme activity in epididymides from well-fed and undernourished mice (50% food restriction for 21 days), a model that alters the epididymal maturation processes. Spectrophotometric analysis revealed NAG activity in mouse epididymis (22.6 +/- 3.7 mU g(-1) tissue; n = 4), being higher in the caput. NAG activity was statistically higher in the caput than in the corpus and in the cauda. No significant differences existed between the caput NAG activity and complete epididymis NAG activity. In undernourished mice, we confirmed changes in epididymal maturation observed previously (i.e. increased number of immature spermatozoa and diminution of the sperm concentration). Concordantly, the epididymides of undernourished mice exhibited decreased enzyme secretory activity, which increased to values similar to those seen in controls following incubation in the presence of testosterone (22.5 +/- 2.6, 12.5 +/- 1.0 and 22.4 +/- 3.7 mU g(-1) tissue, n = 9 in control (n = 7), undernourished (n = 9) and undernourished + testosterone groups (n = 9), respectively). In conclusion, NAG activity was detected in mouse epididymis. Although the present study supports the possibility of using NAG as an epididymal marker, more studies are necessary to effectively prove that NAG activity can be used as an epididymal marker.
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PMID:Neutral alpha-glucosidase activity in mouse: a marker of epididymal function? 1752 1


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