Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P47989 (xanthine oxidase)
 8,633 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Seminal plasma from ejaculates of 10 healthy, fertile volunteers and 63 infertile males was analysed for superoxide dismutase (SOD) and xanthine oxidase (XO) activities using a chemiluminometer. There was not statistically significant difference in the activity of either enzyme between control and infertile populations (113 +/- 74 IU/ml for SOD and 1.17 +/- 0.52 IU/ml for XO) in samples from normozoospermic ejaculates. Sperm progressive motility was positively correlated with SOD activity in seminal plasma of corresponding ejaculates (P < 0.05) and negatively with XO activity (P < 0.001). An 'oxido-sensitive' index was defined as the SOD/XO ratio and was found to be inversely related to sperm progressive motility samples (P < 0.01). Analysing this index among all tested samples of semen including those with pathological spermiograms, as well as normospermic (N) samples we found statistically significant (elevated) differences in oligoasthenoteratospermia (OAT) in comparison with N (P <0.05); OAT samples were also significantly different from oligospermic (O) and oligoteratospermic (OT) samples (P < 0.05). This suggests that the 'oxido-sensitive' index of seminal plasma may be a simple diagnostic factor, useful in the determination of male infertility.
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PMID:Seminal plasma can be a predictive factor for male infertility. 867 28

We have studied the activity of substances (superoxide dismutase [SOD], catalase [Cat], malonaldehyde, xanthine oxidase [XO], nitric oxide [NOx]) participating in oxidative stress. Seminal plasma samples of 147 ejaculates obtained from normal and from infertile males were examined. Activities of SOD, Cat, and XO were measured chemiluminometrically while malonaldehydes and NOx were measured by spectrophotometer in seminal plasma samples. Ejaculates were previously characterized according to World Health Organization andrological criteria (sperm number, motility, and morphology). Procedures were performed in a university laboratory. Statistically significant changes (in comparison to normozoospermic samples) were noted in activities of SOD, XO, and malonaldehyde levels. The SOD activity exceeded values obtained for normozoospermic samples only in oligozoospermia. Otherwise low SOD levels in analyzed infertile subgroups inversely related to elevated malonaldehydes. Because diminished activity of SOD in seminal plasma was associated with increased levels of malonaldehydes and XO, we could postulate some significance of these monitored substances in evaluation of the cause of male infertility.
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PMID:Oxidative stress and male infertility. 888 9

Reactive oxygen species (ROS) have a powerful cytotoxic effect on spermatozoa and have been implicated in spermatozoal dysfunction and male infertility. gamma-Glutamyl transpeptidase (GGT) is essential to the metabolism of the antioxidant glutathione and, as such, is believed to be important in protecting spermatozoa against oxidative stress. The aims of this study were 1) to establish in vitro conditions in which ROS were generated and 2) to determine whether oxidative stress regulated the expression of GGT mRNAs I-IV in the initial segment of the epididymis. Initial segments were collected from adult male rats and incubated in culture media to which ROS-generating compounds, hypoxanthine and xanthine oxidase, were added. By 6.5 hours, incubation of tissue in high-oxidative stress conditions caused a 56% decrease in reduced glutathione concentration, a concomitant 240% increase in oxidized glutathione concentration, and a 25% decrease in adenosine triphosphate concentration. RNase protection analyses demonstrated an approximate 70% up-regulation of GGT mRNAs II-IV in a differential manner, depending on the concentration of oxidizing agents and the type of ROS generated. gamma-Glutamyl transpeptidase mRNA I was not expressed. These results support the hypothesis that expression of GGT mRNAs is regulated by oxidative stress in the initial segment of the rat epididymis.
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PMID:Oxidative stress differentially regulates the expression of gamma-glutamyl transpeptidase mRNAs in the initial segment of the rat epididymis. 953 96

Reactive oxygen species (ROS) inhibit sperm movement and have been implicated in male infertility. In this study, we determined the effects of specific ROS produced by activated leukocytes on human spermatozoa and investigated their metabolic site of action. We used chemiluminescence and electron paramagnetic resonance (EPR) to characterize the ROS generated by both blood and seminal leukocytes. We also determined the effects of these ROS on sperm energy metabolism using biochemical analyses and flow cytometry. Both blood and seminal leukocytes produced the same characteristic ROS which were determined to be hydrogen peroxide (H2O2) and superoxide radicals (O2*-). EPR using the spin trapping technique indicated that superoxide radical-dependent hydroxyl radicals (HO.) were also generated. ROS generated by PMA-stimulated blood leukocytes (2-5 x 10(6)/ml) caused inhibition of sperm movement in 2 h (p < .01). Using the hypoxanthine/ xanthine oxidase (0.5 U/ml) system to generate ROS, we determined that spermatozoa ATP levels, after ROS treatment, were reduced approximately eight-fold in 30 min (0.10 x 10(10) moles/10(6) sperm cells) compared to control (0.84 X 10(-10) moles/10(6) sperm cells) (p < .01). Sperm ATP reduction paralleled the inhibition of sperm forward progression. Neither superoxide dismutase (100 U/ml) nor dimethyl sulfoxide (100 mM) reversed these effects; however, protection was observed with catalase (4 X 10(3) U/ml). Flow cytometric analyses of sperm treated with various doses of H2O2 (0.3 mM-20.0 mM) showed a dose-dependent decrease in sperm mitochondrial membrane potential (MMP); however, at low concentrations of H2O2, sperm MMP was not significantly inhibited. Also, sperm MMP uncoupling with CCClP had no effect on either sperm ATP levels or forward progression. These results indicate that H2O2 is the toxic ROS produced by activated leukocytes causing the inhibition of both sperm movement and ATP production. O2*- and HO. do not play a significant role in these processes. Low concentrations of H2O2 causing complete inhibition of sperm movement and ATP levels inhibit sperm energy metabolism at a site independent of mitochondrial oxidative phosphorylation.
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PMID:Characterization of reactive oxygen species induced effects on human spermatozoa movement and energy metabolism. 1023 30

Apoptotic degeneration of germ cells in cryptorchid testis is associated with an increased level of reactive oxygen species, and may be prevented by antioxidant treatment. The objective of this study was to investigate whether xanthine oxidase inhibitors could confer such protection. Unilateral cryptorchidism was surgically induced in the immature rats, which were then left untreated or treated with xanthine oxidase inhibitors, and the testes were evaluated 7 days after the operation. In the control group, the weight of the cryptorchid testis was decreased to 47% of that of the contralateral scrotal testis. However, administration of a xanthine oxidase inhibitor allopurinol (> or = 1 mg/kg/day) significantly attenuated weight reduction of the cryptorchid testis (68-77% of the contralateral scrotal testis, P < 0.01 versus control). Another highly specific xanthine oxidase inhibitor, BOF-4272, also attenuated cryptorchidism-induced testis regression. The effects of allopurinol were associated with decreased apoptosis in germ cells as evaluated by in-situ staining of fragmented DNA. In testicular cells cultured at 37 degrees C, either allopurinol or BOF-4272 prevented DNA cleavage characteristic of apoptosis. In conclusion, xanthine oxidase inhibitors can inhibit germ cell apoptosis induced by experimental cryptorchidism, and may be considered for treatment of male infertility associated with heat stress.
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PMID:Xanthine oxidase inhibitors suppress testicular germ cell apoptosis induced by experimental cryptorchidism. 1181 14

A range of compounds with a role in oxidative stress were measured in ejaculates from 40 normozoospermic individuals and 93 infertile males. Ejaculates were classified according to WHO criteria. Seminal plasma and the sperm cell fraction were assessed separately for superoxide dismutase (SOD), catalase, xanthine oxidase, capability for singlet oxygen trapping and content of thiobarbituric acid-reactive substances (TBARS). Pathological cases defined as oligozoospermia, asthenozoospermia, or teratozoospermia revealed different backgrounds of oxidative stress as reflected by different levels of tested substances in every type of sperm pathology. In the majority of abnormal ejaculates, a significant increase in intracellular activity of SOD, decreased intracellular levels of catalase, elevated levels of xanthine oxidase and TBARS, and severely impaired singlet oxygen trapping were observed when compared to normozoospermic ejaculates. Interrelationships between SOD and TBARS, and between xanthine oxidase and catalase, appeared to be of key importance when analysed separately in seminal plasma and in spermatozoa or in a combination of both. Elevated xanthine oxidase levels and low capacity for singlet oxygen trapping are statistically significant factors for the evaluation of male infertility which can develop as a result of persistent oxidative stress.
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PMID:Effect of reactive oxygen species and the activity of antioxidant systems on human semen; association with male infertility. 1613 Feb 69