Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.73 (urokinase-type plasminogen activator)
 10,685 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although many risk factors and theories exist in the literature for urinary stone formation, a hypothesis is suggested for the pathogenesis of renal stones. According to the matrix theory, a protein such as uromucoid activates the initial crystallisation process by promoting the formation of calcium oxalate and calcium phosphate crystals as well as clumping in whole urine. We put forward a theory whereby one of the most important factors in the matrix theory would be the composition and concentration of the protein. In support of this hypothesis, emphasis is placed on the activities of urokinase and sialidase.
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PMID:Pathogenesis of kidney stones. 180 56

Gonadotrophin preparations extracted from post-menopausal urine are of low purity and the major protein components are not gonadotrophins. A study was undertaken to identify some of these non-gonadotrophin proteins present in the extracted human urinary gonadotrophin preparations that are commercially available, i.e. Humegon (Organon), HMG Massone (Massone), Metrodin (Serono), Metrodin HP (Serono), Pergonal (Serono) and Progonadyl (Elea). As revealed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) with Coomassie blue staining and Western blotting analysis, these products had electrophoretic protein profiles which differed in the amounts and species of proteins present. With the exception of Metrodin HP, all the other preparations tested contained tumour necrosis factor binding protein-I, transferrin, and immunoglobulin-related proteins. Some of the products contained in addition: urokinase, Tamm-Horsfall glycoprotein and epidermal growth factor. Recently, a highly purified human urinary follicle stimulating hormone (FSH) preparation (Metrodin HP) became available. In this preparation human FSH represents > 95% of the total proteins (approximately 10,000 IU of FSH/mg of protein). Metrodin HP was demonstrated to be the purest preparation tested, with none of the above-mentioned contaminants detected.
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PMID:Composition of commercial gonadotrophin preparations extracted from human post-menopausal urine: characterization of non-gonadotrophin proteins. 771 47

Many hypotheses have been proposed for renal stone formation. It has been argued that with infection-induced renal stones the hydrolysis of urea by bacterial urease increases urinary pH, with consequent stone formation. Unfortunately, this theory is not applicable to the micro-organisms that do not produce urease (e.g. Escherichia coli). It has been recently reported that E. coli reduces the urinary urokinase activity of male rats, but does not influence the urinary sialidase activity. This study has now been expanded to the urease-producing bacteria Proteus mirabilis, Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa and Micrococcus luteus. Subcutaneous injections with these bacteria were found to significantly (P < 0.003) reduce the UK activity of extrarenally obstructed kidneys. The urease-producing mammalian skin bacterium, M. luteus, was, however, the exception (P = 0.1079). In contrast to S. epidermidis, P. aeruginosa and M. luteus (P < 0.0213), P. mirabilis and S. aureus had no effect on renal sialidase activity (P < 0.4047). These results may explain why Proteus species are predominant in infection-induced renal stones. According to the urokinase-sialidase hypothesis, a decrease in urinary urokinase activity should increase the uromucoid levels, whilst no effect on the urinary sialidase activity should favour conversion of urinary uromucoid to mineralizable matrix. These conditions may lead to renal stone formation. An increase in urinary pH resulting from urease-producing micro-organisms will increase salt precipitation on the uromucoid. It is thus concluded that urease-producing bacteria may play a double role in renal stone formation.
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PMID:In vivo effects of urease-producing bacteria involved with the pathogenesis of infection-induced urolithiasis on renal urokinase and sialidase activity. 883 91

Renal stone formation is a complex multifactorial disease, and it is believed that the initial step in the pathogenesis of urolithiasis must be the precipitation of an organic matrix of mucoproteins followed by precipitation of minerals onto this matrix. An important factor in this process may be the activity and/or concentration of the urinary enzyme, urokinase, which would affect the level of urinary mucoproteins such as uromucoid. In support of this hypothesis, ELISA studies were conducted to investigate the urokinase concentrations in urine obtained from males (22-60 years) with and without renal stones. These results showed a significant decrease in urinary urokinase concentration of renal stone patients which, once again, underlines the possible involvement of urokinase in renal stone formation. Therefore, it seems logical to conclude that urokinase may play an integral role in this multifactorial disease.
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PMID:Does urokinase play a role in renal stone formation? 924 9