We investigated the binding form of IgE to platelets and the relationship between IgE and platelet function. When the paraformaldehyde (PFA)-fixed platelets were incubated with the IgE-protein from human myeloma (M-IgE), the platelet-associated IgE (PAIgE) of Glanzmann's thrombasthenic platelets was significantly less than that of healthy control. The binding of M-IgE to the healthy PFA-fixed platelets was in-hibited by the pretreatment of the platelets with monoclonal anti-GPIIb/IIIa complex antibody or Arg-Gly-Asp-Ser (RGDS), but not monoclonal anti-GP I b antibody or heat aggregated IgG. When the unfixed platelets which had been activated with PAF or ADP were incubated with the M-IgE, the PAIgE increased significantly. The increased PAIgE hardly effected on not only the platelet aggregation or platelet secretion but also the increase of [Ca2+]i by activation. These results suggest that IgE binds to not the Fc-receptor but the GPIIb/IIIa-related receptor on the platelet surface. This binding increases with the platelet activation, whereas the increased IgE dose not appear to effect on the platelet function.
The effects of ONO-3307 (4-sulfamoylphenyl 4-guanidinobenzoate methanesulfonate), a new synthetic protease inhibitor, on endotoxin-induced experimental disseminated intravascular coagulation (DIC) were studied in rats. Experimental DIC was induced by 4 hour sustained infusion of endotoxin at a dose of 100mg/kg. The rats were infused continuously with ONO-3307 at 1, 10, 100μg/kg/h into a femoral vein for 4 hour. Simultaneously with the agent infusion, endotoxin was administered into the contralateral femoral vein. A protective effect against DIC was noted in the rats treated with 10 or 100μg/kg/h of ONO-3307 in the following parameters: fibrinogen and fibrin degradation products, platelet count, fibrinogen level, prothrombin time, partial thromboplastin time and the number of renal glomeruli with fibrin thrombi. These results demonstrated that ONO-3307 reduces the extent of changes of the coagulation parameters caused by DIC.
Effect of prostaglandin E1 on blood loss from polytetrafluoroethylene (PTFE) graft was studied in an animal model. After the abdominal aorta of rabbits was replaced with PTFE graft, it was punctured with a straight needle (120μm in diameter) under systemic heparinization (50U/kg). Blood pressure, blood loss from the puncture site, and bleeding time were measured in various concentrations. Then the luminal surfaces of PTFE graft around puncture sites were analyzed by scanning electron microscopy (SEM). Various concentrations of PGE1 (0, 0.05, 0.1, 0.2μg/kg/min) was continuously infused via ear vein after the bolus intravenous injection of heparin (50U/kg). Although there were no changes in systemic blood pressure, bleeding time and blood loss were increased significantly by PGE1 administration (0.1 and 0.2μg/kg/min) in comparison to the control (heparin alone). SEM revealed that the hemostatic plug formation at the puncture site was suppressed by PGE1 in a dose dependent manner. These results indicate that PGE1 administration should be avoid or used with a low dose in vascular reconstruction using prosthesis, especially mode of PTFE.
It is the purpose of this report to evaluate Thrombin-Antithrombin III Complex (TAT) determination by an ELISA. SDS-PAGE was used to study the thrombin-antithrombin III interaction. In purified systm, when AT-III (1U/ml) was incubated with thrombin (250NIH U/ml), a complex of Molecular Weight (Mol. Wt) 81500 in this electrophoretic system was formed. As time goes by, this band disappeared as a complex of appearent Mol. Wt 78000 was formed. The amount of TAT increased from 4.3±0.23mg/ml to 10.59±0.57mg/ml gradually. In the present of heparin, a complex of Mol. Wt 81500 was formed immediately. As a passage of time, this band disappeared as complex of appearent various low. Mol. Wt were formed and the amount of TAT decreased gradually. From these observations, it was considered that measurable TAT of Mol. Wt 81500 and 78000 were detected in this method. TAT was determinated in plasma from 30 normal subjects, 30 patients with DIC, 15 patients with sepsis, 5 patients with deep vein thrombosis. The results were as follows; normal subjects 2.1±1.2ng/ml (mean±SD), DIC 28.9±43.5ng/ml, sepsis 21.4±11.0ng/ml, deep vein thrombosis 7.6±10.7ng/ml. There did not exist a definite correlation between the levels of TAT and AT-III in patients with these diseases. In the case of a patient with AT-III deficiency, TAT was markedly elevated and decreased following the infusion of AT-III concentrate and FOY. Heparin cofactor activity decreased and FDP-D dimer increased immediately TAT was elevated. These results indicate that the quantitative assay TAT would be a sensitive parameter for specific detection of the clotting pathway.
We determined tissue plasminogen activator (t-PA) activity, antigen, and plasminogen activator inhibitor-1 (PAI-1) antigen levels, and performed the statistical analyses of correlation with biochemical parameters used for physical check up in 81 volunteers hospitalized for healthy examination. Transaminases (GOT, GPT), γ-glutamyl transpeptidase (γ-GTP), zink sulfate turbidity test (ZTT), thymol turbidity test (TTT), leucine aminopeptidase (LAP), lactate dehydrogenase (LDH), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL), uric acid (UA), calcium (Ca), creatinine (CRN), fasting blood sugar (FBS) had significant correlation with t-PA activity, antigen, and PAI-1 antigen. A canonical correlation coefficient was significant between the object variables (t-PA activity, antigen, index and PAI-1 antigen) and the explanatory variables (GOT, GPT, TC, TG, CRN, UA, γ-GTP, HDL, FBS). The results suggest that fibrinolytic balance (t-PA, PAI-1) in blood may be affected by the parameters of the liver function, the uricotelic metabolism, the hyperlipidemia, or the hyperglycemia.
Recently the relationship between sulfhydryls and cGMP has been discussed in the several biological processes. While captopril, but not enalapril, is a sulfhydryl-containing angiotensin converting enzyme (ACE) inhibitor, we have previously reported that it decreased PGI2 generation in cultured human vascular endothelial cells. So we aimed to investigate the implication of cGMP and sulfhydryls in the regulatory mechanisms of PGI2 generation including with which induced by captopril with reference to Ca++ kinetics, Bradykinin and Ca ionophre A23187 enhanced PGI2 generation, and the cytosolic free Ca++ concentration ([Ca++]i). And 8-bromo cGMP increased intracellular cGMP concentration ([cGMP]i), and decreased PGI2 generation without change in [Ca++]i. Sulfhydryl radical containing compounds such as captopril, N-acetylcysteine and glutathione decreased PGI2 generation via the increased [cGMP]i. However an ACE inhibitor without sulfhydryl radicals, enalapril had no effect on them. Through these results it was suggested that enalapril might be more beneficial than captopril for the management of hypertensive patients with thromboembolic complications, and is was considered to be an important factor whether the vasoactive substances contain the sulfhydryls or not for the examinination of their effects on PGI2 generation.
We have recently reported that nafamostat mesilate (FUT-175), a synthetic serine protease inhibitor, inhibited the binding of fibrinogen to ADP-stimulated human platelets in an antagonistic manner. In respect to the similar effect of FUT-175 to ArgGly-Asp-Ser (RGDS), synthetic peptide constituted cell attachment domain of fibronectin, on fibrinogen binding to stimulated platelets, we have examined the effects of synthetic protease inhibitors on both fibronectin binding to thrombin-stimulated platetets and fibronectin-mediated cell attachment. To exclude the direct inhibitory effect of the agents against thrombin, paraformaldehyde-fixed thrombin-stimulated platelets which expressed fibronectin-binding sites were used in this study. Among the synthetic inhibitors examined, FUT-175 and FUT-5923 which have amidinonaptol in their structure as active inhibitory sites, blocked the binding of 125I-fibronectin to thrombin-stimulated platelets dose-dependently. 125I-fibrinogen binding to ADP-stimulated fixed platelets was also inhibited by both FUT-175 and FUT-5923. These data indicated that the inhibition of amidinonaphtol derivatives was not via blockade of binding site expression. Attachment of normal rat kidney fibroblasts to fibronectin-coated plate was inhibited by these amidinonaphtol derivatives, dose dependently. The agents were also affected fibronectin dependent cellular spreading. These results suggest that the inhibitory effects of amidinonaphtol derivatives on the cellular interaction with these adhesive proteins might be related to conformational characteristics, not to their inhibitory activities against proteases.
Leukocyte elastase in plasma and serum was measured by an enzyme-linked immunosorbent assay (ELISA) and the amidolysis using a synthetic substrate for leukocyte elastase, Suc-Ala-Tyr-Leu-Val-pNA. Leukocyte elastase (ELP) values in plasma and serum from healthy donors were 125±35 and 341±57ng/ml (ELISA) and 139±55 and 222±69ng/ml (amidolysis), respectively. But ELP values in serum separated by a blood collecting tube, AUTO-SEP, increased to 545±219ng/ml (ELISA) and 277±95ng/ml (amidolysis). Correlation coefficients between ELP in plasma and serum from patients were 0.36 (ELISA) and 0.86 (amidolysis). Furthermore, the variations of ELP values were approximately parallel when ELP in plasma and serum continuously obtained from some patients was measured by the amidolysis. Excepting leukocytes number, fibrinogen level was closely connected with the elevation of serum ELP level. The increase of fibrinogen in blood from patients was accompanied by the elevation of ELP and FDP without the decrease of plasminogen and antithrombin III. The increase of fibrinogen in inflammation may possibly cause fibrinogenolysis by ELP.