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Biomedical subjects

O Matsuo

Publications and source records attributed to O Matsuo.

At least 127 records · Page 7Linked to original sources
PubMed1983

Substrate specificity of tissue plasminogen activator and urokinase as determined with synthetic chromogenic substrates.

Three different synthetic chromogenic substrates )H-glutamylglycyl-L-arginine-p-nitroanilide (S-2227), pyro-glutamyl-glycyl-L-arginine-p-nitroanilide (S-2444), and H-D-isoleucyl-L-prolyl-L-arginine-p-nitroanilide (S-2288] were investigated for use in the measurement of plasminogen activator activity with high molecular weight urokinase (H-UK), low molecular weight urokinase (L-UK), and tissue plasminogen activator (TPA). The three substrates were hydrolyzed by both TPA-type and UK-type plasminogen activator. As regards the amidolytic activity of S-2227, TPA exhibited a weaker amidolytic activity, and L-UK a stronger activity. In the case of the amidolytic activity of S-2444, no great difference between the three activators was observed in terms of Vmax. As regards the amidolytic activity of S-2288, L-UK exhibited a stronger activity, and TPA a weaker activity. It is suggested that the molecular size of the synthetic chromogenic substrate was too small when compared to natural substrate (fibrin), and therefore that fibrin-binding sites around the catalytic site in TPA are not recognized.

Chromogenic Compounds↗
PubMed1983

Production of plasminogen activator in a melanoma cell line.

A melanoma cell line (Bowes) was found to produce plasminogen activator even on its growing phase, and the rate of plasminogen activator production was rather constant. The production of plasminogen activator was proportional to the cell number. Morphologically, no specific features for plasminogen activator production were seen. Plasminogen activator was observed in the lysate of this cell line only when the cell number was large. The extracellular plasminogen activator activity was higher than the intracellular plasminogen activator activity, suggesting the existence of a secretion mechanism for the plasminogen activator.

Cell Count↗
PubMed1983

The role of plasminogen activator in ovulation.

The role of plasminogen activator in ovulation was investigated using the inhibitor, trans-aminomethylcyclohexane carboxylic acid (t-AMCHA). In the regular cycle rat, the plasminogen activator activity of the follicles increased from the diestrus to the estrus phase. In the latter phase, a proteolytic enzyme which was not inhibited by t-AMCHA appeared. After ovulation, the plasminogen activator activity decreased. When ovulation was induced in immature rats by pregnant mare serum gonadotrophin and human chorionic gonadotrophin, remarkable fibrinolytic activity appeared in the ovaries immediately before ovulation. When t-AMCHA was given in the ovulation-induced rats, the fibrinolytic activity of the ovaries was suppressed, the number of ovulated ova decreased and the timing of ovulation was delayed. When t-AMCHA solution was given to rats in the proestrus phase, ovulation was almost completely suppressed, but aprotinin solution exerted no effect on ovulation. These results suggest that plasminogen activator is a key enzyme in ovulation, and that the chain reaction from plasminogen activator to proteolytic enzyme (including collagenase) is of greater importance than that of plasminogen activator to plasmin.

Animals↗
PubMed1982

Determination of alpha 2-plasmin inhibitor in body fluids.

A sensitive method was developed to determine alpha 2 PI at very low concentrations. The minimal measurable concentration of alpha 2 PI was 0.5 ng/assay tube. Using this method, the alpha 2 PI in plasma, urine, amniotic fluid and cerebrospinal fluid was estimated. The mean values and standard deviation for plasma were 5.63 +/- 1.34 mg/dl in 25 males, and 5.29 +/- 1.62 mg/dl in 8 females; in the urine, 0.46 +/- 0.41 microgram/dl in 82 male samples, and 0.69 +/- 0.27 microgram/dl in 8 female samples; in amniotic fluid, 4.13 +/- 2.38 micrograms/dl in 16 samples; and in cerebrospinal fluid, 24.4 +/- 6.6 microgram/dl in 9 samples. The alpha 2 PI level in amniotic fluid was not correlated with the state of the pregnant mother, with that of the baby, or with the protein content or pH of the amniotic fluid.

Amniotic Fluid↗
PubMed1982

Comparative study of the activity of high and low molecular weight urokinase in the presence of fibrin.

The fibrinolytic or thrombolytic activity of low molecular weight urokinase (LMW-UK) and high molecular weight urokinase (HMW-UK) is not significantly different when measured in a bovine fibrin plate method, in a circulating plasma system containing a 125I-labelled human fibrin clot, or on 125I-fibrin films in culture plates using normal or alpha 2-antiplasmin depleted human plasma. In a human fibrin plate method however HMW-UK was found to be more active than LMW-UK. In a purified system on human 125I-fibrin films the activation of native or modified human plasminogen by HMW-UK was also found to be more effective than by LMW-UK. Using a clot lysis test system we did not observed a different inhibition of LMW-UK and HMW-UK upon incubation in human plasma. This is in contrast with previous reports that HMW-UK is inhibited more rapidly in human plasma than LMW-UK. In a purified system the inhibition rate of LMW-UK and HMW-UK by alpha 2-antiplasmin is the same (rate constants at 25 degree C of 167 +/- 9 M-1s-1 and 171 +/- 5 M-1s-1 respectively). The clinical trials available at present used doses of urokinase which were in excess of those required to obtain a maximal fibrinolytic effect. This might explain why in these trials no difference was observed between the thrombolytic effect of LMW-UK and HMW-UK, while in vitro HMW-UK appeared to be more effective. However, one should always be careful to extrapolate in vitro observations as such to the in vivo situation encountered during thrombolytic therapy.

Animals↗
PubMed1982

Low molecular weight trypsin-plasmin inhibitors isolated from papain treated urinary trypsin inhibitor.

Papain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chrymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotryspin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10(-7) - 2.12 X 10(-6) M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors of plasmin was thought to be different from that to trypsin or chymotrypsin.

Amino Acids↗
PubMed1982

Immunochemical studies of high and low molecular forms of urokinase.

The immunochemical properties of high and low molecular forms of urokinase (HMW-UK, MW 53,000, 124,000 IU/mg protein; LMW-UK, MW 32,000, 230,000 IU/mg protein) were studied with specific antisera against the functionally active heavy chain (H chain, MW 31,000, 201,000 IU/mg protein) and the light chain (L chain, MW 18,000) of HMW-UK. Using a double immunodiffusion technique, LMW-UK did not demonstrate L chain antigenicity in the molecule. Anti-L-chain serum exerted no effect on LMW-UK and the H chain, but anti-H-chain serum strongly inhibited the fibrinolytic activity of all the active enzymes (HMW-UK, LMW-UK, and H chain). Anti-L chain serum was found to exert an antifibrinolytic effect on HMW-UK.

Animals↗
PubMed1982

Thrombolysis with human extrinsic (tissue-type) plasminogen activator in dogs with femoral vein thrombosis.

Extrinsic (tissue-type) plasminogen activator (plasminogen activator) was isolated either as a single-chain or as a two-chain molecule from the culture medium of a human melanoma cell line. The thrombolytic activity of both molecular forms of activator was investigated in beagle dogs with an experimental femoral vein thrombosis and compared with that of urokinase. The 125I-fibrinogen-labeled thrombus was formed in an isolated 4-cm segment of the vein, aged for 30 min, and the thrombolytic substances were infused over a 4-h period. The degree of thrombolysis was measured 2 h later as the difference between the injected and recovered 125I. In six control animals with a saline infusion the extent of thrombolysis was 16.3 +/- 3.8% (mean +/- SEM), in five dogs receiving 100,000 IU urokinase, 17.4 +/- 3.7% (P less than 0.4) and in four dogs with 1,000,000 IU urokinase 40.6 +/- 4.8% (P less than 0.001). Infusion of 100.000 IU single-chain plasminogen activator in five dogs resulted in 3.5 +/- 7.8% lysis (P less than 0.05) and of 100,000 IU two-chain plasminogen activator in five dogs in 60.1 +/- 10.8% (P less than 0.001). Infusion of 300,000 IU one-chain plasminogen activator yielded 57.5% lysis and of the same amount of two-chain plasminogen activator 72.9%. Significant activation of plasminogen, consumption of alpha 2-antiplasmin, and fibrinogen breakdown in plasma was only observed in animals receiving the high doses of urokinase but not in the saline, plasminogen activator, or the low-dose urokinase groups. It is thus concluded that in this thrombosis model human extrinsic plasminogen activator has a higher specific thrombolytic effect that urokinase. Plasminogen activator also appears to induce thrombolysis without systemic fibrinolytic activation and fibrinogen breakdown.

Animals↗
PubMed1982

Effect of urokinase on fibrinolysis and fibrinogenolysis.

The thrombolytic (fibrinolytic) effect of the urinary plasminogen activator, urokinase (UK), was compared with its fibrinogenolytic effect, using an artificial circulating system, and in in vivo pulmonary embolus and femoral vein thrombosis models. The thrombus lysing efficiency (fibrinolysis/fibrinogenolysis) was, in all cases, below 1.00, indicating that fibrinogenolysis is a primary function of UK while fibrinolysis is a secondary one.

Animals↗
PubMed1981

Comparison of the relative fibrinogenolytic, fibrinolytic and thrombolytic properties of tissue plasminogen activator and urokinase in vitro.

The relative fibrinogenolytic, fibrinolytic and thrombolytic properties of human tissue plasminogen activator and human urokinase were compared in purified systems, in whole human plasma and in a system composed of a radioactive human blood clot (125I-fibrinogen) hanging in circulating human plasma. The human tissue plasminogen activator was highly purified from the culture fluid of a human melanoma cell line. In purified systems composed of fibrinogen of fibrin, plasminogen and alpha 2-antiplasmin as well as in whole plasma, tissue plasminogen activator digested fibrin without degrading fibrinogen significantly. Urokinase did not have this specific fibrinolytic effect. In the circulating plasma system, the degree of fibrinolysis was proportional to the amount of activator added, tissue plasminogen activator being about 10 times more efficient than urokinase. In addition, tissue plasminogen activator appeared to cause negligible fibrinogen degradation. Tissue plasminogen activator still induced significant thrombolysis at a concentration of 10 IU per ml whereas no effect of urokinase was observed at 20 IU per ml. Infusion of 100 IU (1 microgram) of tissue plasminogen activator per ml resulted in moderate activation of the fibrinolytic system as judged from a decrease of plasminogen and alpha 2-antiplasmin to 40-50 percent. Nevertheless, extensive fibrinolysis (50 to 80 percent of radioactivity released after 12 hrs) and only very limited fibrinogenolysis were observed. An equivalent amount of urokinase (100 IU per ml) only induced approximately 15 percent lysis in 12 hrs. At higher concentrations of urokinase (260 IU per ml or more) extensive activation of the fibrinolytic system was obtained as evidenced by a depletion of plasminogen, alpha 2-antiplasmin and fibrinogen. This was associated with extensive fibrinolysis (approximately 60 percent after 12 hrs). It is concluded that human tissue plasminogen activator is a more specific and effective fibrinolytic-thrombolytic agent than human urokinase.

Endopeptidases↗