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PubMedDate not supplied

The place of the peritoneovenous shunt in the treatment of ascites.

The peritoneovenous shunt (PVS) is a safe procedure; all of its complications have been found to be preventable. Disseminated intravascular coagulopathy (DIC) can be a life threatening complication but has been completely eliminated by draining the ascitic fluid at the time of surgery, as it is caused by the introduction of excessive quantities of peritoneal fluid into the venous system. Peritoneal fluid is rich in tissue plasminogen activator (TPA), which is inhibited by epsilon aminocaproic acid. This substance has been successfully used to treat postshunt coagulopathy. The salt retention associated with ascites is related to a diminished plasma volume, a condition further aggravated by diuretic drugs. A PVS should be inserted if the patient does not respond to a salt restricted diet. Occult peritonitis occurs in 10% of cirrhotic ascites. The shunt does not prevent this, and a high percentage of late shunt failures are caused by fibrinopurulent debris in the valve. The valve system should not contain a pump, which disseminates infection and causes fatal emboli; pumping and flushing are seldom remedial and often dangerous. Because the complications of the shunt are all preventable, the indications for the shunt should be liberalized.

Ascites↗
PubMed1990

Fibrin glue-antibiotic suspension in the prevention of prosthetic graft infection.

UNLABELLED: The following study was done to assess whether fibrin glue-antibiotic suspension (FGAS) can prevent infection of a PTFE vascular graft in a contaminated wound. METHODS: FGAS was made by combining cryoprecipitate with a mixture of bovine thrombin, aminocaproic acid, and tobramycin (5 mg/cc thrombus). Antibiotic activity was documented by in vitro kinetics which revealed initial elutions to be greater than 8,000 mu gm/cc and elutions at 4 days to be greater than 2 mcg/cc. Twelve dogs had a 1-cm section of infrarenal aorta replaced with a PTFE graft that had been bathed in a 2-cc solution of E. coli 3 x 10(8) CFU/ml and S. aureus 3 x 10(8) CFU/ml. Both organisms were sensitive to tobramycin and cefonicid. Dogs were divided into three groups of four. Group I had a contaminated PTFE graft placed and no further therapy. Group II had a contaminated PTFE graft placed and sealed with fibrin glue. Group III had a contaminated PTFE graft placed and sealed with FGAS. All three groups received daily IV cefonicid. RESULTS: Group I: Four of four dogs were reoperated on the fourth day for suspected sepsis and all four had pseudoaneurysms (one ruptured). Three of four were culture positive for S. aureus and two of four positive for E. coli. Group II: Four of four died of anastomotic disruption by the third day. Four of four were culture positive for S. aureus and E. coli. Group III: All four dogs survived and were sacrificed on Day 17: all anastomoses were normal. Animal survival was significantly associated with the treatment given (p = 0.0025). Three of four tissue cultures of the grafts were weakly positive for S. aureus and one of four for E. coli and Pseudomonas. Serum tobramycin levels were negligible at 12, 24, 72, and 96 hours. CONCLUSIONS: The data show that FGAS was associated with a reduction in vascular graft infection and pseudoaneurysm formation after exposure to a standardized bacterial inoculum. Whether complete eradication of all organisms can be achieved with higher doses of tobramycin is as yet undetermined.

Aneurysm, Infected↗
PubMedDate not supplied

Furosemide: progress in understanding its diuretic, anti-inflammatory, and bronchodilating mechanism of action, and use in the treatment of respiratory tract diseases.

Accumulated experimental and clinical data suggest that adrenocorticosteroids and/or endogenous ouabain-like substances may play an important role in the mechanism of furosemide diuretic action. It was reported that the drug is highly bound in the adrenals, lungs, kidney, spleen, and liver. In patients with liver cirrhosis, furosemide exerted a markedly decreased natriuretic effect compared with normal subjects, and the plasma levels of circulating endothelin and atrial natriuretic factor (ANF) were significantly elevated. In neonates, after administration of furosemide, the urinary excretion of endothelin-1 and aldosterone increased markedly, and it is known that endothelin may release ANF and aldosterone in a dose-dependent manner. Furosemide was used to stimulate zona glomerulosa, whereas ANF decreased the production of steroids in zona glomerulosa and fasciculata cell culture owing to stimulation by various factors. Because the concomitant use of ANF and furosemide appeared to be diuretically effective in newborns after cardiac surgery, one may suggest that furosemide competes with ANF for its effects on the adrenals. Furosemide administered by inhalation exerted a protective effect on allergic and perennial nonallergic rhinitis and was effective in preventing the postsurgical recurrence of nasal polyposis. The drug can also be used as an antiasthmatic agent. In preterm ventilator-dependent infants with chronic lung disease, aerosolized furosemide improved pulmonary function with no marked effect on diuresis. In adults and children with asthma, furosemide exerted a protective effect against bronchoconstriction induced by several indirect stimuli similar to that of disodium cromoglycate or nedocromil. Aerosolized furosemide had a preventive effect also on bronchoconstriction induced by inhaled lysine acetylsalicylate in patients with aspirin-sensitive asthma. In high-dose beclomethasone-dependent asthma, inhaled lysine acetylsalicylate and furosemide exerted a mutually potentiating antiasthmatic activity, allowing considerable sparing of the inhaled steroid. It is proposed that this effect may be explained by the corticosteroid-sparing action of lysine released from the lysine acetylsalicylate molecule because similar beneficial effects were also obtained after the concomitant use of epsilon-aminocaproic acid (whose chemical structure is almost the same as that of lysine) and prednisone. Furosemide exhibited an anti-inflammatory effect through inhibition of production and release of cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha from peripheral mononuclear cells, which may have a beneficial effect on local inflamed tissue imbalance in the ratio of different cytokines, thus improving the sensitivity of target cells to endogenous glucocorticosteroids.

Adult↗
PubMed1996

Binding of human plasminogen and lactoferrin by Helicobacter pylori coccoid forms.

The interactions between Helicobacter pylori spiral and coccoid forms, extracellular matrix (ECM) and plasma proteins were studied in an 125I-labelled protein assay. The range of binding of collagen V, plasminogen, human lactoferrin (HLf) and vitronectin to coccoid forms of H. pylori NCTC 11637 was 26-48%. In contrast, binding of radiolabelled fibronectin and collagen types I and III was low (3-8%). The coccoid forms of 14 strains of H. pylori showed significant HLf binding (median 26%). With plasminogen, no significant difference was found between binding to the coccoid (median = 13%) and spiral (median = 12%) forms, of 13 of the 14 strains of H. pylori tested; the exception was strain NCTC 11637. 125I-plasminogen showed a dose-dependent binding to both the coccoid and spiral forms. Plasminogen binding to both forms was specific; the binding was inhibited by non-labelled plasminogen, plasmin, lysine, EACA (epsilon-aminocaproic acid) but not by fetuin or various carbohydrates. Similarly, HLf binding was found to be specific and was inhibited by non-labelled HLf and BLf. The coccoid forms showed either similar or enhanced ECM binding capabilities compared with the spiral forms. As the binding of ECM proteins may be an important mechanism of tissue adhesion for various pathogenic bacteria, the coccoid differentiated form of H. pylori can be considered as an infective form in the pathogenesis of helicobacter infection and type B gastritis.

Collagen↗
PubMed2003

Binding of Candida albicans enolase to plasmin(ogen) results in enhanced invasion of human brain microvascular endothelial cells.

Infection by the human opportunistic fungal pathogen Candida albicans has been increasing over recent years. In an attempt to understand the molecular mechanism of Candida invasion across host tissues, the relationship of C. albicans enolase to human plasminogen/plasmin was investigated. C. albicans enolase is a cell-surface protein and an immunodominant antigen in infected patients' sera. Plasminogen is an abundant plasma protein. Several lines of evidence support the binding of C. albicans enolase to human plasminogen. Firstly, it was found that various Candida strains were able to bind to plasminogen and its active form, plasmin. Secondly, recombinant Candida enolase was retained in a nickel-chelating affinity column matrix that can bind (125)I-labelled plasminogen or plasmin in a dose-dependent manner. Plasmin(ogen)-specific inhibitors, such as epsilon -aminocaproic acid and aprotinin, can effectively block plasmin-binding activity. Thirdly, as with many plasminogen receptors, binding of Candida enolase to plasmin(ogen) is lysine-dependent, whereas little inhibition occurred with arginine, aspartate and glutamate. Fourthly, immobilized enolase enhanced plasminogen's affinity for streptokinase at least tenfold, as demonstrated by its activation of plasmin activity. To elucidate the biological significance of this result, it was demonstrated that the plasmin(ogen)-bound Candida cells were able to induce fibrinolysis activity in a matrix-gel assay. Furthermore, plasmin-bound Candida cells had an increased ability to cross an in vitro blood-brain barrier system. The results given here indicate that Candida enolase is a plasminogen- and plasmin-binding protein and that the interaction of C. albicans enolase with the plasminogen system may contribute to invasion of the tissue barrier.

Blood Vessels↗
PubMed2005

Treatment of factor XI inhibitor using recombinant activated factor VIIa.

A 30-year-old female with severe factor XI deficiency of 0-2% acquired factor XI inhibitor following many infusions for fresh frozen plasma (FFP) for surgical procedures starting at 4 years of age. Seven months before this inhibitor was diagnosed, surgery was complicated by prolonged bleeding resistant to FFP, requiring epsilon aminocaproic acid (EACA) and surgical packing. The inhibitor was measured at 2.2 Bethesda units, 7 months since the last FFP. The inhibitor was confirmed as specific anti-XI and anti-XIa binding by patient's IgG to immobilized factor XI and factor XIa from whole plasma and purified IgG. For repair of a painful anterior cruciate ligament (ACL) defect she was given recombinant factor VIIa (rVIIa) at 90 mug kg(-1), starting one-half hour preoperatively and continued every 2 h for 8 h when haemostasis was complete. Thereafter the rVIIa was given every 3 h for two doses, and then every 4 h for four doses at which time she was discharged on EACA which was continued for 6 days. There was excellent haemostasis during and following the surgery. There was no evidence of consumptive coagulopathy, with no change in the fibrinogen, platelet count, or D-D dimer; and no increase of platelet factor 4, beta-thromboglobulin, or prothrombin fragment F 1.2. The thrombin-antithrombin complex increased over baseline after 24 h. There was no postoperative deep vein thrombosis or pulmonary embolus. In this patient with a factor XI inhibitor, the recombinant factor VIIa was effective and safe, ensuring adequate haemostasis with no thrombotic complications. This product which was designed for patients with inhibitors to factor VIII or factor IX, and factor VII deficiency, has now been given successfully to four patients with factor XI inhibitors.

Adult↗
PubMed1997

Analysis of the mechanism of lipoprotein(a) assembly.

We have assessed the ability of a battery of purified recombinant apolipoprotein(a) (r-apo(a)) derivatives to bind to immobilized low-density lipoprotein (LDL) by ELISA. Removal of the apo(a) kringle IV type 8 and type 9 sequences dramatically reduced apo(a) binding to LDL. The binding of apo(a) to LDL was effectively inhibited by arginine, lysine, the lysine analogue epsilon-aminocaproic acid and proline; comparable inhibition was observed using the 17K and KIV5-8 r-apo(a) derivatives, suggesting a direct role for sequences contained in the latter species in mediating the initial non-covalent interactions which precede specific disulfide bond formation. We also determined that r-apo(a) binds directly to a synthetic apoB peptide spanning amino acid residues 3732-3745; this interaction appeared to be mediated by sequences present in apo(a) kringle IV types 8 and 9, and could be inhibited by arginine, lysine and proline. The results of this study indicate that the efficiency of Lp(a) assembly is a direct function of the initial non-covalent interactions between apo(a) and LDL; in addition, these studies suggest that Cys3734 in apoB mediates covalent linkage with apo(a) by virtue of the ability of the apoB sequences surrounding this residue to directly interact with apo(a) KIV type 9.

Apolipoproteins A↗
PubMed2004

Nonlysine-analog plasminogen modulators promote autoproteolytic generation of plasmin(ogen) fragments with angiostatin-like activity.

We recently discovered several nonlysine-analog conformational modulators for plasminogen. These include SMTP-6, thioplabin B and complestatin that are low molecular mass compounds of microbial origin. Unlike lysine-analog modulators, which increase plasminogen activation but inhibit its binding to fibrin, the nonlysine-analog modulators enhance both activation and fibrin binding of plasminogen. Here we show that some nonlysine-analog modulators promote autoproteolytic generation of plasmin(ogen) derivatives with its catalytic domain undergoing extensive fragmentation (PMDs), which have angiostatin-like anti-endothelial activity. The enhancement of urokinase-catalyzed plasminogen activation by SMTP-6 was followed by rapid inactivation of plasmin due to its degradation mainly in the catalytic domain, yielding PMD with a molecular mass ranging from 68 to 77 kDa. PMD generation was observed when plasmin alone was treated with SMTP-6 and was inhibited by the plasmin inhibitor aprotinin, indicating an autoproteolytic mechanism in PMD generation. Thioplabin B and complestatin, two other nonlysine-analog modulators, were also active in producing similar PMDs, whereas the lysine analog 6-aminohexanoic acid was inactive while it enhanced plasminogen activation. Peptide sequencing and mass spectrometric analyses suggested that plasmin fragmentation was due to cleavage at Lys615-Val616, Lys651-Leu652, Lys661-Val662, Lys698-Glu699, Lys708-Val709 and several other sites mostly in the catalytic domain. PMD was inhibitory to proliferation, migration and tube formation of endothelial cells at concentrations of 0.3-10 microg.mL(-1). These results suggest a possible application of nonlysine-analog modulators in the treatment of cancer through the enhancement of endogenous plasmin(ogen) fragment formation.

Amino Acids↗
PubMed2003

Diagnosis and management of gastrointestinal bleeding in patients with hereditary hemorrhagic telangiectasia.

OBJECTIVE: Our aim was to report our experience with treating GI bleeding in patients with hereditary hemorrhagic telangiectasia (HHT). METHODS: Consecutive patients with GI bleeding referred to the Yale University Vascular Malformation Center underwent clinical evaluation and endoscopy. Hb and blood transfusion requirements for 1 yr before and after evaluation were documented. Patients with a mean Hb or= 12 units packed red blood cells (PRBC)/yr were defined as patients with significant bleeding. Drug therapies, including ethinyl estradiol/norethindrone, danazol, and aminocaproic acid, were prescribed on an individual patient basis. RESULTS: The study included 43 HHT patients with a mean age of 57 yr. Endoscopy revealed telangiectases in the esophagus (1/41), stomach (33/41), duodenum (33/41), jejunum (5/9), and colon (10/32). Patients with > 20 telangiectases visualized on esophagogastroduodenoscopy had a significantly lower mean Hb of 7.9, compared with 9.4 (p = 0.007), and a trend toward higher blood transfusion requirements. Non-HHT-related causes of GI bleeding were diagnosed in four patients. During a mean follow up of 18.9 months, the group of 40 patients with HHT-related bleeding had improvements in their mean Hb and blood transfusion requirements. CONCLUSIONS: Some HHT patients with GI bleeding improve on drug therapies, but others fail. Transfusion-dependent GI bleeding is difficult to manage, and optimal management may include both medical and endoscopic treatments.

Adult↗
PubMed1993

Mycoplasma cells stimulate in vitro activation of plasminogen by purified tissue-type plasminogen activator.

In an in vitro direct assay with tissue-type plasminogen activator (tPA), plasminogen and the chromogenic substrate S-2251, the ability of Mycoplasma fermentans KL4 to stimulate tPA-mediated activation of plasminogen to plasmin was studied. Mycoplasma cells markedly enhanced the activation of plasminogen by tPA in a concentration-, temperature- and pH-dependent manner. Nonidet P-40 (0.01%), sonication, and freezing and thawing of the cells substantially increased the stimulatory effect of mycoplasma on tPA activity. In contrast, the activation of plasminogen by urokinase was refractory to mycoplasma cells. The mycoplasma-mediated stimulation of tPA activity was prevented by epsilon-aminocaproic acid (EACA), a lysine analogue known to block lysine-binding sites (LBS) in plasminogen and tPA. Among several Mycoplasma fermentans strains tested, incognitus strain demonstrated the highest stimulation activity. These results suggest that mycoplasma cells interact with LBS in tPA and plasminogen to enhance plasminogen activation.

Enzyme Activation↗
PubMed1993

Immobilization of plasminogen on Escherichia coli flagella.

The interaction of plasminogen with flagella of Escherichia coli was investigated. Plasminogen bound to flagella purified from E. coli LE392, a commonly used cloning host, and E. coli IH3069, an O25H1 strain isolated from a case of newborn bacteremia. The binding was inhibited by the lysine analog epsilon-aminocaproic acid, suggesting involvement of the lysine-binding Kringle domains of plasminogen in the binding. Purified flagella enhanced the formation of plasmin activity in the presence of tissue-type plasminogen activator; a similar enhancement was observed with flagella-expressing LE392 cells.

Binding Sites↗
PubMed1978

Dextran-induced lowering of prekallikrein proactivator and prekallikrein in rat plasma.

The intravenous injection into rats of dextran (average MW 70,000) 10 mg/100 g caused marked hypotension after a delay of about 5 minutes. Blood samples collected by cardiac puncture at this time were tested for the amounts of prekallikrein activator (PKA) and kallikrein after acetone- and then kaolin activation of the plasminogen-free plasma. PKA was assayed by measuring the initial rate of release of benzoyl arginine esterase (BAEe) activity in a preparation of partially purified human prekallikrein, and kallikrein was assayed by measuring the BAEe esterase activity. Significant reductions of both parameters were registered, and the amount of high molecular weight kininogen (HMWK) present in the plasma was also reduced. Pretreatment of the rats with epsilon-aminocaproic acid intraperitoneally (200-300 mg/100 g) abolished the dextran-caused decreases in the plasma levels of the above mentioned factors, and reduced the fall in blood pressure. The addition of purified human HMWK to the plasma before the acetone activation procedure was started, increased the yield of PKA activity in the final enzyme preparation. When PKA was assayed after kaolin activation of plasma at 0 degrees using the method developed by Laake & Vennerød (1973a & b) for the determination of PKA (activated factor XII) in human plasma, no differences were registered between plasma from rats treated with dextran and plasma obtained from control rats. It is suggested that the low PKA activity of the acetone activated enzyme preparation from plasma of rats treated with dextran was due to the loss of HMWK or a fraction of HMWK.

Acetone↗
PubMed1984

Immunology of the monobactam aztreonam.

To assess the immunological cross-reactivity of the monobactam antibiotic aztreonam (AZ), rabbits were immunized with protein conjugates of benzylpenicillin, cephalothin (CEPH), and AZ. The resulting antibenzylpenicilloyl (BPO) and anti-CEPH rabbit antibodies showed negligible cross-reactivity with AZ conjugated to human serum albumin (AZ-HSA), whereas anti-AZ showed negligible cross-reactivity with BPO-HSA and CEPH-HSA. Unlike benzylpenicillin and CEPH, unconjugated AZ was as effective as AZ conjugated to epsilon aminocaproic acid (AZ-EACA) in inhibiting the binding of homologous antibody. Studies with various analogs of AZ confirmed that immunoglobulin G (IgG) anti-AZ was entirely side-chain specific. The inhibition of the binding of human IgE anti-penicilloyl to BPO-HSA was studied in the presence of AZ-EACA, BPO-formyl lysine, and CEPH-EACA. Whereas CEPH-EACA displayed 3% cross-reactivity with BPO-lysine, AZ-EACA showed little or no cross-reactivity (much less than 0.9%). To assess the immunogenicity of AZ in humans, IgE and IgG antibodies were measured in sera from 36 healthy male volunteers receiving 0.5 or 1 g intravenously or intramuscularly every 8 h for 7 days. None of the subjects had detectable preexisting IgE reactive with AZ or demonstrated an IgE response to antibiotic administration. Four subjects gave evidence for naturally occurring IgG cross-reactive with AZ, but only one subject demonstrated a rise in IgG levels after exposure to AZ. This anti-AZ IgG did not cross-react with BPO or CEPH conjugates of bovine thyroglobulin and was completely side-chain specific. These studies suggest that AZ displays very low immunological cross-reactivity with other beta-lactam antibiotics and may be only weakly immunogenic in humans.

Animals↗
PubMed2002

Inhibition of nanobacteria by antimicrobial drugs as measured by a modified microdilution method.

Compounds from 16 classes of antimicrobial drugs were tested for their abilities to inhibit the in vitro multiplication of nanobacteria (NB), a newly discovered infectious agent found in human kidney stones and kidney cyst fluids from patients with polycystic kidney disease (PKD). Because NB form surface calcifications at physiologic levels of calcium and phosphate, they have been hypothesized to mediate the formation of tissue calcifications. We describe a modified microdilution inhibitory test that accommodates the unique growth conditions and long multiplication times of NB. This modified microdilution method included inoculation of 96-well plates and determination of inhibition by periodic measurement of the absorbance for 14 days in cell culture medium under cell culture conditions. Bactericidal or bacteriostatic drug effects were distinguished by subsequent subculture in drug-free media and monitoring for increasing absorbance. NB isolated from fetal bovine serum (FBS) were inhibited by tetracycline HCl, nitrofurantoin, trimethoprim, trimethoprim-sulfamethoxazole, and ampicillin at levels achievable in serum and urine; all drugs except ampicillin were cidal. Tetracycline also inhibited multiplication of isolates of NB from human kidney stones and kidney cyst fluids from patients with PKD. The other antibiotics tested against FBS-derived NB either had no effect or exhibited an inhibitory concentration above clinically achievable levels; the aminoglycosides and vancomycin were bacteriostatic. Antibiotic-induced morphological changes to NB were observed by electron microscopy. Bisphosphonates, aminocaproic acid, potassium citrate-citric acid solutions, and 5-fluorouracil also inhibited the multiplication of NB in a cidal manner. Insights into the nature of NB, the action(s) of these drugs, and the role of NB in calcifying diseases may be gained by exploiting this in vitro inhibition test system.

Anti-Bacterial Agents↗
PubMed2003

Synthesis of imidazol-2-yl amino acids by using cells from alkane-oxidizing bacteria.

Sixty-one strains of alkane-oxidizing bacteria were tested for their ability to oxidize N-(2-hexylamino-4-phenylimidazol-1-yl)-acetamide to imidazol-2-yl amino acids applicable for pharmaceutical purposes. After growth with n-alkane, 15 strains formed different imidazol-2-yl amino acids identified by chemical structure analysis (mass and nuclear magnetic resonance spectrometry). High yields of imidazol-2-yl amino acids were produced by the strains Gordonia rubropertincta SBUG 105, Gordonia terrae SBUG 253, Nocardia asteroides SBUG 175, Rhodococcus erythropolis SBUG 251, and Rhodococcus erythropolis SBUG 254. Biotransformation occurred via oxidation of the alkyl side chain and produced 1-acetylamino-4-phenylimidazol-2-yl-6-aminohexanoic acid and the butanoic acid derivative. In addition, the acetylamino group of these products and of the substrate was transformed to an amino group. The product pattern as well as the transformation pathway of N-(2-hexylamino-4-phenylimidazol-1-yl)-acetamide differed in the various strains used.

Acetamides↗
PubMed1969

Standardized procedure for determination of staphylocoagulase.

A simple standardized procedure for the determination of staphylocoagulase, based on thrombin clotting time measurement with euglobulin, has been developed. A standard euglobulin solution containing 0.25% of clottable protein, 0.01 M epsilon-aminocaproic acid, and 20 units of heparin per ml is employed. One unit of staphylocoagulase is defined as the amount of the enzyme which clots this standard euglobulin solution in 25 sec.

Coagulase↗
PubMed1990

Receptors for human plasminogen on gram-negative bacteria.

A total of 188 strains representing 11 species of gram-negative bacteria were examined for the ability to interact with human plasminogen. Highly purified human plasminogen was labeled with 125I, and its uptake by different bacterial strains was measured. All 14 strains of Haemophilus influenzae and all 13 strains of Branhamella catarrhalis tested were positive with respect to plasminogen uptake. Also, eight species belonging to the family Enterobacteriaceae were tested, and of those, Proteus mirabilis demonstrated the most substantial uptake, with 28 of 39 strains taking up more than 10% of the plasminogen. Ten strains of Pseudomonas aeruginosa were also tested, of which seven showed uptake values higher than 10%. With H. influenzae and B. catarrhalis strains, Scatchard analysis indicated a two-phase receptor interaction, one more-avid receptor with a Kd of 6 to 8 nM and 2,000 to 2,500 sites per bacterium and a second receptor with a Kd of 50 to 80 nM and 9,000 sites per bacterium. With Pseudomonas aeruginosa strains, a single receptor interaction was detected with a Kd of 60 nM and the number of sites was estimated as 8,000 per bacterium. Scatchard analysis with strains of P. mirabilis indicated binding of a less-specific nature. However, plasminogen uptake by this species could be reduced by 50% by the addition of 2 mM unlabeled plasminogen. This estimate of Kd, as well as uptake studies with plasminogen fragments, suggests different properties of this receptor. With all receptor types, the addition of plasmin-aprotinin complex inhibited plasminogen uptake, which demonstrates that both forms of the molecule react with the same receptors. Plasminogen uptake could be eliminated by the addition of lysine or epsilon-aminocaproic acid, which suggests that the lysine-binding sites of the plasminogen molecule are involved in the receptor-ligand interaction.

Aprotinin↗