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)

Hitherto, seminal plasma maltase has been measured with maltose as substrate; this method is time consuming and lacks specificity. The use of a synthetic substrate, p-nitrophenol-alpha-D-glucopyranoside, allows accurate and rapid determination of this activity. When maltase is added to the incubation medium (the substrate and reduced glutathione in potassium phosphate buffer, pH 6.8), maintained at 37 degrees C, hydrolysis of the original substrate to p-nitrophenol goes at a constant rate during 4 h. Under optimal conditions of incubation, the Michaelis constant of the reaction, calculated by the Hanes method, was 2.92 +/- 0.84 (SD) X 10(-3) for six different semen samples. Isomaltase appeared to be absent from seminal plasma. The enzyme is stable to freezing and slow thawing and can be stored for at least 26 days at -80 degrees C. Its molecular weight is 259 000. Tris(hydroxymethyl)aminomethane (pH 6.8) exerts a noncompetitive inhibition on the enzyme activity. In 68 men 23 to 45 years old, whose semen analyses were normal, the seminal plasma maltase activity was 467 +/- 135 (SD) mU/g of protein. It was generally decreased in patients with infertility disorders.
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PMID:P-Nitrophenol-alpha-D-glucopyranoside as substrate for measurement of maltase activity in human semen. 2 9

A specific assay based on the spectrophotometric determination of the release of p-nitrophenol from p-nitrophenol-alpha-D-glucopyranoside by maltase has been used to measure the activity of the enzyme in seminal plasma and in homogenates of accessory reproductive organs. Specific activity of seminal plasma maltase was 467 muU/mg of proteins in 68 fertile men, decreased significantly in varicocele (296 muU/mg), in azoospermia (246 muU/mg) and in vasectomized patients (62 muU/mg). Application of ion exchange chromatography on DEAE-Sephadex A-50 columns led to the demonstration that maltase activity of seminal plasma and of cytosols from normal reproductive organs was recovered in three different fractions. Maltase activity is thus frequently decreased in infertility.
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PMID:Origin of maltase and variations in infertile men. 36 66

Samples of sperm have been obtained from 95 who consulted us for infertility. In each case seminal plasma was examined for levels of alpha-1,4-glucosidase and L-carnitine. Our results have led us to fix the threshold value of 42.6 mlU per ejaculate for alpha-1,4-glucosidase and 960 nanomoles of L-carnitine below those levels that we thought occur where the origin of the oligospermia is obstructive (series 1 patients). In series 2 patients the cause of the oligospermia purely being secretory, there is normal epididymal function and therefore the excretory doubts are proven. It is not impossible to have both pathologies because we have found this in men of the intermediate groups C and D. We have found that there is a correlation between the presence of epididymal pathology and a drop in epididymal markers which can be found in severe oligospermia (which can be epididymal in origin and not testicular). Also when there is non abnormalities in the spermogram. This last situation can occur in "invisible" abnormalities of spermaturation in the epidymus.
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PMID:[The value of the level of alpha-1,4-glucosidase and seminal l-carnitine in patients with oligoasthenospermia]. 182 86

The literature pertaining to epididymal proteins and their functions in fertilization is reviewed. Animal studies have indicated that specific epididymal proteins may be involved in aspects of sperm motility, sperm-zona binding and the acrosome reaction. If analogous proteins in the human exist, use could be made of them in the andrology clinic. Currently, only one specific epididymal protein (alpha-glucosidase) is routinely measured for semen analysis. Glucosidase secretion, in addition to reflecting inflammation of the organ, is used in conjunction with other markers of human fertility to identify patients with ductal occlusion for whom bypass operations may be useful therapy. Glucosidase inhibitors have been used to improve the assay, by establishing true semen blank values, and to quantify histochemical activity in frozen tissue sections. From its localization in the human corpus and cauda epididymidis, neutral glucosidase can not be used to identify occlusion in the proximal regions of the duct. Other proteins may be valuable markers of these regions. In the future, other specific proteins of epididymal origin found in seminal fluid could well illuminate dysfunction of the organ in cases of infertility or be end-points of the disruptive action of drugs aimed at the epididymis.
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PMID:Secretory proteins from the epididymis and their clinical relevance. 213 67

Azoospermic semen was obtained from 39 vasectomized men and 93 patients consulting for infertility. The latter underwent bioclinical investigations including measurement of plasma FSH and testicular biopsies. Carnitine content and alpha-glucosidase activity in semen samples were measured. The activity of alpha-glucosidase was determined systematically by a semiquantitative microtechnique and was verified by a spectrophotometric assay. A positive correlation was observed between carnitine and alpha-glucosidase activity. Both parameters were severely diminished in semen from the vasectomized men and the patients suffering from a complete obstruction of the genital tract. Enzyme activity was the most discriminant parameter in terms of sensitivity and specificity. The measurement of alpha-glucosidase in semen is a simple and sensitive method for determining the origin of azoospermia when used in conjunction with assays for plasma FSH.
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PMID:Alpha-glucosidase as a specific epididymal enzyme marker. Its validity for the etiologic diagnosis of azoospermia. 352 16

Certain ejaculate infections can be traced back to sexually transmitted microorganisms, such as Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma urealyticum and Trichomonas vaginalis. To varying extents, these microorganisms cause such classical genital infections as urethritis, epididymitis and prostatitis as well as subclinical genital tract infections. Several different pathomechanisms are under discussion for infection of the ejaculate: reduction of spermatogenesis resulting from testicular damage, autoimmune processes induced by inflammation, direct influence on the spermatozoal function, disturbances in spermatozoal transport, secretory dysfunction of the male accessory sex glands and leukocytospermia with secondary influence on ejaculate parameters. The relevance of these microorganisms for the localization of the inflammatory process within the genital tract are discussed in detail. Their importance for male fertility is a matter of debate. In particular, the significance of C. trachomatis and U. urealyticum, both of which are detectable in the urethra, is still uncertain and cannot be assessed conclusively. Further information allowing delimitation of an infection resulting from bacterial colonization may be provided, on the one hand, by biochemical markers for an inflammatory reaction and indicators of an immune response in the ejaculate, e.g. PMN elastase, complement C3, or coeruloplasmin, and on the other hand, by secretion markers such as alpha-glucosidase, PSA and phosphatase. Whether the assessment of these markers and indicators can help to clarify the inflammatory origin of infertility in individual cases remains doubtful.
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PMID:[Infections of the ejaculate by sexually transmissible pathogens]. 751 3

Ornidazole (400 mg kg-1 day-1) given by oral gavage rendered male rats infertile by 6.6 +/- 0.7 days (mean +/- SEM, n = 9, range 3-10) after beginning the treatment and fertility returned within 5-10 days after treatment with ornidazole for 6-7 days. At 200 mg ornidazole kg-1 day-1, fertility was reduced but total infertility was not achieved. No differences were found in the percentage motility of spermatozoa recovered from any region of the epididymides of ornidazole-treated rats compared with controls. However, computer aided sperm analysis revealed significantly lower straight-line and average path velocities in ornidazole-treated animals (400 mg kg-1 day-1) for spermatozoa from the distal regions of the tract than for controls. Curvilinear velocity was significantly lower than that of controls in the distal corpus and cauda regions. The motility characteristics of spermatozoa from animals receiving 200 mg ornidazole kg-1 day-1 were lower than, but not significantly different from, motility in controls. There were no differences between the total protein, L-carnitine, glycerophosphocholine or total alpha-glucosidase content in epididymal homogenates from fertile control and infertile ornidazole-treated animals. Spermatozoa released from the cauda epididymidis of untreated rats into ornidazole solutions displayed no changes in the percentage motility up to 20 mmol l-1 and were only depressed at 50 mmol l-1. All velocities revealed a biphasic response with an initial increase in motility and then inhibition at higher concentrations, but a significant difference from velocities in the absence of orindazole was evident only for straight line velocity (VSL) at 50 mmol l-1.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Induction of reversible infertility in male rats by oral ornidazole and its effects on sperm motility and epididymal secretions. 802 76

Neutral alpha-glucosidase activity was measured in seminal plasma of 30 patients consulting for infertility with a variety of disorders, and compared with 25 normal controls. Significantly more of the study populations (asthenozoospermia, 4/6; oligozoospermia, 3/5; azoospermia 8/15) had a neutral alpha-glucosidase activity less than 10 mIU/mL as compared with control samples (3/25). Also the mean (+/- SD) neutral alpha-glucosidase activity in patients with asthenozoospermia (11.7 +/- 9.2) oligozoospermia (11.3 +/- 7.2), and post vasectomy azoospermia (5.3 +/- 3.4) was significantly (p < .05) less than ejaculate from controls (21.2 +/- 14). A seminal alpha-glucosidase level of 10 mIU/mL appears to be a useful discriminatory marker in the diagnosis of epididymal obstruction or dysfunction.
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PMID:New discriminatory level for glucosidase activity to diagnose epididymal obstruction or dysfunction. 855 28

Treatment of couple infertility due to male subfertility by means of intra-uterine insemination (IUI) gives better results, in terms of per cycle and total cumulative pregnancy rate, if sperm preparation is performed using a discontinuous Percoll gradient than if centrifugation-resuspension is used. Also, the minimal semen requirements for successful IUI are lower with the former technique. Optimal epididymal function, with total alpha-glucosidase activity in seminal plasma > 83 IU/mL or Schorr stain result > 60%, is associated with a high probability of success of IUI [odds ratio (OR) = 11.1 and 9.4 respectively; p < 0.01]. If semen contains > 2.3 million white blood cells per mL or more than 13 million spermatozoa/mL with grade a motility the success rate is decreased (OR = 0.25 and 0.30 respectively; p < 0.05 and p < 0.01). It is concluded that IUI is a highly successful treatment in specific cases of male subfertility, provided that the correct technique of sperm preparation is used.
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PMID:Statement on intra-uterine insemination. 871 64

In order to improve the selection of couples for intrauterine insemination (IUI) because of longstanding primary infertility of alleged male origin, we have performed a prospective study measuring conventional and advanced analysis of sperm characteristics, the hypoosmotic swelling test, the Shorr stain, the acidified aniline blue stain and alpha-glucosidase activity in seminal plasma, of 89 couples with no demonstrable abnormality of the female partner. Twenty-four couples attained spontaneous conception, 23 were successful within six cycles of IUI, and 42 remained without conception in spite of IUI during six unstimulated cycles. The proportion and concentration of spermatozoa with progressive motility was significantly lower (P < 0.01) in the successful IUI cases than in the couples attaining spontaneous conception, and the lower quartile value was lower in the former than in the latter. There were less pregnancies among IUI treated couples when sperm concentration and motility were within the range of normal fertile men, or when the concentration of white blood cells was elevated. More pregnancies occurred when markers of epididymal function, namely the result of the Shorr stain and alpha-glucosidase measurement, were normal. Total progressive motility and the result of the Shorr stain were the only independent variables selected by logistic regression to discriminate between successful and failed IUI cases. It is concluded that only a limited group of couples may benefit from IUI.
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PMID:The value of semen characteristics and tests of sperm function in selecting couples for intra-uterine insemination. 880 Nov 36


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