Evaluation of Uridine Metabolism in Human and Animal Spermatozoa |
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| Authors: | T Niemeyer C Dietz L Fairbanks I Schroeder-Printzen R Henkel M Löeffler |
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| Institution: | 1. Institute for Physiological Chemistry , Philipps-University , Marburg, Denmark;2. Purine Research Unit , Guy's Hospital , London, United Kingdom;3. Department of Urology , Justus-Liebig-University , Giessen, Denmark;4. Department of Medical Biosciences , University of the Western Cape , Bellville, South Africa;5. Institute for Physiological Chemistry , Philipps-University , Marburg, Germany |
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| Abstract: | The objective of this study was to elucidate the role of uridine for spermatozoa, since this pyrimidine nucleoside was found in millimolar concentration in human seminal plasma. Here, the degradative activity of uridine-phosphorylase EC 2.4.2.3] and the salvage activity of uridine kinase EC 2.7.1.48] were detected in human spermatozoa. HPLC analysis depicted the uptake of exogeneous 14C-labelled adenine, but not of uridine and of hypoxanthine, into nucleotide pools of boar spermatozoa. On addition of uridine, the computer-assisted semen analysis (CASA) of human cells revealed a reduction of the percentage of motile spermatozoa in contrast to an elevation of some velocity parameters. It is concluded that exogeneous uridine could function as suppressor for early capacitation and as a substrate for phosphorolysis, if ribose is needed, rather than to satisfy a demand for intracellular pyrimidine nucleotides. |
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| Keywords: | Uridine phosphorylase Kinase Nucleotide pools CASA Spermatozoa |
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