RESUMEN
BACKGROUND: Chronic Chagas disease (CCHD) associated with Systemic Arterial Hypertension (SAH) is frequently found in areas where the disease is endemic. The pathogenesis of patients with both pathologies (CCHD-SAH) is unsettled. Nitric Oxide (NO) and Kinins are important players in the myocardial inflammation process in experimental CCHD. No previous study has addressed this question in patients with CCHD, particularly in those with CCHD-SAH. Accordingly, this study was undertaken in an attempt to contribute to the understanding of the pathogenesis of patients with CCHD-SAH. METHODS: Thirty-seven patients with a positive serology for Chagas disease were enrolled; 15 had CCHD alone, 22 had CCHD-SAH (abnormal ECG/Doppler echocardiogram plus a systolic blood pressure > 140 mmHg or diastolic blood pressure > 90 mmHg on admission), and 11 had SAH alone. Thirty healthy individuals matched by age and sex served as controls. Plasma High-molecular (Hkg) and low-molecular weight (LKg) kininogens, plasma kallikrein levels (Pkal and Tcal), Kininase II, and plasma NO were measured. RESULTS: HKg and LKg were lower in CCHD-SAH patients in comparison with other groups (P < .0001). Pkal and Tcal were higher in CCHD-SAH patients in comparison with the other groups (P< .0001). Kininase II levels were similar in SAH, CCHD, and CCHD-SAH patients, but lower in comparison with controls (P< .0001). NO levels were similar in CCHD and CCHD-SAH patients, but higher in comparison with SAH patients and controls (P > .0001). CONCLUSION: Such findings suggest increased Kinin and NO activity in patients with CCHD-SAH, thus contributing to the understanding of the pathogenesis of this condition.
Asunto(s)
Presión Arterial , Enfermedad de Chagas/sangre , Hipertensión/sangre , Cininas/sangre , Óxido Nítrico/sangre , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Brasil/epidemiología , Estudios de Casos y Controles , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/fisiopatología , Femenino , Humanos , Hipertensión/diagnóstico , Hipertensión/epidemiología , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Regulación hacia ArribaRESUMEN
BACKGROUND: The kallikrein-kinin system (KKS) has several direct and indirect effects on cells and cellular mediators involved in the inflammatory process. Studies about inflammation on percutaneous transluminal angioplasty with stent (PTA/stent) to treat peripheral arterial disease (PAD) in humans are scarce. The matrix metalloproteinases (MMPs) are calcium-dependent zinc-containing endopeptidases expressed in various cells and tissues such as fibroblasts, inflammatory cells, and, smooth muscle cells. Changes in the extracellular matrix (ECM) take place in the pathogenesis of many cardiovascular pathologies. MMPs and their inhibitors (tissue inhibitors of metalloproteinases [TIMPs]) are crucial in ECM remodeling in both physiologic and pathologic conditions. The aim of this study was to evaluate the role of the KKS and the MMP metabolism, which are important mediators that may contribute to tissue repair, in the process of arterial restenosis due to intimal hyperplasia in the femoropopliteal segment with the aim of developing new interventions. METHODS: Thirty-nine consecutive patients were selected (regardless of ethnic group, age, or sex) for revascularization, who underwent PTA/stent of the femoropopliteal segment. Twenty-five patients with the same clinical characteristics who were scheduled for diagnostic angiography but not subjected to PTA/nitinol stent were also selected. The concentrations in blood of total and kininogen fractions were evaluated using immunoenzymatic methods. Plasma kallikrein was evaluated by the colorimetric method. Tissue kallikrein was evaluated by the spectrophotometric method. The activity of kininase II was measured by fluorometric analysis. Quantification of MMPs was performed by zymography, which is an electrophoresis technique, and TIMPs were measured by enzyme-linked immunosorbent assay. RESULTS: Among the 31 patients who completed the survey, there were 10 cases of angiographically defined restenosis of >50%, and 21 cases without restenosis. There was an increase in the concentrations of the substrates (high-molecular-weight kininogens and lower molecular weight kininogens) and enzymes (plasma and tissue kallikrein) in patients with restenosis, indicating activation of this inflammatory pathway in these patients. The activity of kininase II was not significantly different between the groups of patients studied. There were no statistical differences between restenosis and no restenosis patients for both MMPs and TIMPs dosage, but there is an upward trend of MMPs in time 6 months in patients with restenosis. CONCLUSIONS: With the aim of identifying factors contributing to restenosis after endovascular intervention, this study showed evidence of high activation of the KKS in the pathologic inflammatory process of PTA/stent restenosis. In the other hand, it could not show participation of metalloproteinase metabolism in PTA/stent restenosis.
Asunto(s)
Angioplastia de Balón/instrumentación , Arteria Femoral , Calicreínas/sangre , Cininas/sangre , Metaloproteasas/sangre , Enfermedad Arterial Periférica/enzimología , Enfermedad Arterial Periférica/terapia , Arteria Poplítea , Stents , Inhibidores Tisulares de Metaloproteinasas/sangre , Anciano , Angioplastia de Balón/efectos adversos , Biomarcadores/sangre , Estudios de Casos y Controles , Constricción Patológica , Femenino , Arteria Femoral/diagnóstico por imagen , Humanos , Hiperplasia , Masculino , Persona de Mediana Edad , Neointima , Enfermedad Arterial Periférica/sangre , Enfermedad Arterial Periférica/diagnóstico , Arteria Poplítea/diagnóstico por imagen , Radiografía , Recurrencia , Factores de TiempoRESUMEN
The generation of bradykinin (BK; Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg) in blood and kallidin (Lys-BK) in tissues by the action of the kallikrein-kinin system has received little attention in non-mammalian vertebrates. In mammals, kallidin can be generated by the coronary endothelium and myocytes in response to ischemia, mediating cardioprotective events. The plasma of birds lacks two key components of the kallikrein-kinin system: the low molecular weight kininogen and a prekallikrein activator analogous to mammalian factor XII, but treatment with bovine plasma kallikrein generates ornitho-kinin [Thr6,Leu8]-BK. The possible cardioprotective effect of ornitho-kinin infusion was investigated in an anesthetized, open-chest chicken model of acute coronary occlusion. A branch of the left main coronary artery was reversibly ligated to produce ischemia followed by reperfusion, after which the degree of myocardial necrosis (infarct size as a percent of area at risk) was assessed by tetrazolium staining. The iv injection of a low dose of ornitho-kinin (4 microg/kg) reduced mean arterial pressure from 88 +/- 12 to 42 +/- 7 mmHg and increased heart rate from 335 +/- 38 to 402 +/- 45 bpm (N = 5). The size of the infarct was reduced by pretreatment with ornitho-kinin (500 microg/kg infused over a period of 5 min) from 35 +/- 3 to 10 +/- 2% of the area at risk. These results suggest that the physiological role of the kallikrein-kinin system is preserved in this animal model in spite of the absence of two key components, i.e., low molecular weight kininogen and factor XII.
Asunto(s)
Bradiquinina/análogos & derivados , Cardiotónicos/uso terapéutico , Cininas/efectos de los fármacos , Infarto del Miocardio/prevención & control , Vasodilatadores/uso terapéutico , Enfermedad Aguda , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Bradiquinina/uso terapéutico , Captopril/farmacología , Pollos , Modelos Animales de Enfermedad , Precondicionamiento Isquémico Miocárdico , Cininas/sangre , Cininas/fisiología , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Cuidados Preoperatorios , Resistencia Vascular/efectos de los fármacosRESUMEN
The generation of bradykinin (BK; Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg) in blood and kallidin (Lys-BK) in tissues by the action of the kallikrein-kinin system has received little attention in non-mammalian vertebrates. In mammals, kallidin can be generated by the coronary endothelium and myocytes in response to ischemia, mediating cardioprotective events. The plasma of birds lacks two key components of the kallikrein-kinin system: the low molecular weight kininogen and a prekallikrein activator analogous to mammalian factor XII, but treatment with bovine plasma kallikrein generates ornitho-kinin [Thr6,Leu8]-BK. The possible cardioprotective effect of ornitho-kinin infusion was investigated in an anesthetized, open-chest chicken model of acute coronary occlusion. A branch of the left main coronary artery was reversibly ligated to produce ischemia followed by reperfusion, after which the degree of myocardial necrosis (infarct size as a percent of area at risk) was assessed by tetrazolium staining. The iv injection of a low dose of ornitho-kinin (4 µg/kg) reduced mean arterial pressure from 88 ± 12 to 42 ± 7 mmHg and increased heart rate from 335 ± 38 to 402 ± 45 bpm (N = 5). The size of the infarct was reduced by pretreatment with ornitho-kinin (500 µg/kg infused over a period of 5 min) from 35 ± 3 to 10 ± 2 percent of the area at risk. These results suggest that the physiological role of the kallikrein-kinin system is preserved in this animal model in spite of the absence of two key components, i.e., low molecular weight kininogen and factor XII.
Asunto(s)
Animales , Bradiquinina/análogos & derivados , Cardiotónicos/uso terapéutico , Cininas/efectos de los fármacos , Infarto del Miocardio/prevención & control , Vasodilatadores/uso terapéutico , Enfermedad Aguda , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Presión Sanguínea/efectos de los fármacos , Bradiquinina/uso terapéutico , Pollos , Captopril/farmacología , Modelos Animales de Enfermedad , Precondicionamiento Isquémico Miocárdico , Cininas/sangre , Cininas/fisiología , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología , Cuidados Preoperatorios , Resistencia Vascular/efectos de los fármacosRESUMEN
Post-exercise hypotension is an important event for blood pressure regulation, especially in hypertensive individuals. Although post-exercise hypotension is a well-known phenomenon, the mechanism responsible is still unclear. The kallikrein-kinin system is involved in blood pressure control, but its role in post-exercise hypotension has not yet been investigated. Thus, the purpose of this study was to investigate the involvement of the vasodilators bradykinin and des-Arg(9)-BK and kallikrein activity in post-exercise hypotension promoted by 35 min of cycle ergometer (CE) or circuit weight-training (CWT) bouts in normotensive and hypertensive individuals. A significant decrease in mean arterial pressure at 45 and 60 min after CE and 45 min after CWT was observed in normotensive individuals. Hypertensive values of mean arterial pressure were significantly reduced at 45 and 60 min after CE and at 60 min after CWT. Before exercise, plasma bradykinin concentrations and kallikrein activity were higher in hypertensive compared to normotensive volunteers. Kinin levels increased in the groups evaluated at the end of the training period and 60 min post-exercise. These data suggest that the kallikrein-kinin system may be involved in post-exercise hypotension in normotensive and hypertensive individuals subjected to CE and CWT bouts.
Asunto(s)
Ejercicio Físico/fisiología , Salud , Hipertensión/sangre , Hipertensión/fisiopatología , Cininas/sangre , Adulto , Presión Sanguínea , Humanos , Calicreínas/sangre , Ácido Láctico/sangre , Masculino , Óxido Nítrico/sangreRESUMEN
Several lines of evidence in experimental animals indicate that the kinin system may participate in the pathogenesis of envenomation by the Tityus serrulatus (Ts) scorpion sting, but there are no studies in humans with regard to this system. In this study, we evaluated the plasma levels of high-molecular (HKg) and low-molecular (LKg) weight kininogens (detected by ELISA), the activities of plasma or tissue kallikreins and kininase II (enzymatic action upon selective substrates), and the Ts plasma venom levels (ELISA). A total of 27 patients (12 males) aged 12-72 were evaluated immediately at hospital admittance. According to the severity of envenomation, patients were classified as mild (n = 15), moderate (n = 8), and severe cases (n = 4). Controls were paired for age and sex. Plasma venom levels were associated with the severity of envenomation. Severe cases presented lower levels of LKg in relation to mild and controls. Inverse correlations were seen between LKg levels and the venom concentration. The results of this study suggested that the kinin system may participate in the pathogenesis of human Ts envenomation and knowledge about this system may be useful to develop new strategies to reduce the damage caused by scorpion envenomation.
Asunto(s)
Glucemia , Calicreínas/metabolismo , Cininas/efectos de los fármacos , Venenos de Escorpión/efectos adversos , Picaduras de Arañas/sangre , Adolescente , Adulto , Anciano , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Quininógenos/sangre , Cininas/sangre , Masculino , Persona de Mediana Edad , Venenos de Escorpión/sangre , Índice de Severidad de la Enfermedad , Picaduras de Arañas/clasificaciónRESUMEN
There are few studies regarding the evaluation of the kinin system in patients with systemic lupus erythematosus (SLE). In this study, we evaluated the plasma levels of high-molecular weight kininogen (HKg), low-molecular weight kininogen (LKg) and plasma kallikrein; the plasma activity of tissue kallikrein and kininase II, and urinary kallikrein and kininase II activities in patients presenting with active lupus nephritis. A total of 30 patients (29 women) aged 21-62 years (median = 39) and 30 controls matched to the patients for sex and age were studied. Patients presenting with other underlying diseases or using drugs, which could interfere with the kinin system, were excluded. HKg and LKg levels were indirectly evaluated by ELISA. Plasma kallikrein, tissue kallikrein, and kininase II were evaluated by their enzymatic activity on selective substrates. The Mann-Whitney test was used for statistical analysis. HKg, LKg and plasma kallikrein levels were significantly increased in patients (p < 0.001, for each comparison). Similarly, tissue kallikrein and kininase II activities were significantly increased in plasma and urine of patients (p <0.001, for each comparison). In urine, the activities of tissue kallikrein and kininase II were at least seven times higher than those seen in the plasma of patients. These results indicate that the kinin system is involved in the acute manifestations of lupus nephritis. Kinins may facilitate immunecomplex deposition and may induce the release of other pro-inflammatory mediators, including cytokines actively involved in the pathogenesis of lupus nephritis.
Asunto(s)
Cininas/metabolismo , Nefritis Lúpica/metabolismo , Adulto , Femenino , Humanos , Calicreínas/sangre , Quininógenos/sangre , Quininógenos/orina , Cininas/sangre , Cininas/orina , Nefritis Lúpica/sangre , Nefritis Lúpica/orina , Masculino , Persona de Mediana Edad , Peso Molecular , Peptidil-Dipeptidasa A/sangre , Peptidil-Dipeptidasa A/metabolismo , Peptidil-Dipeptidasa A/orinaRESUMEN
The kallikrein-kinin system is complex, with several bioactive peptides that are formed in many different compartments. Kinin peptides are implicated in many physiological and pathological processes including the regulation of blood pressure and sodium homeostasis, inflammatory processes, and the cardioprotective effects of preconditioning. We established a methodology for the measurement of individual kinin peptides in order to study the function of the kallikrein-kinin system. The levels of kinin peptides in tissues were higher than in blood, confirming the primary tissue localization of the kallikrein-kinin system. Moreover, the separate measurement of bradykinin and kallidin peptides in man demonstrated the differential regulation of the plasma and tissue kallikrein-kinin systems, respectively. Kinin peptide levels were increased in the heart of rats with myocardial infarction, in tissues of diabetic and spontaneously hypertensive rats, and in urine of patients with interstitial cystitis, suggesting a role for kinin peptides in the pathogenesis of these conditions. By contrast, blood levels of kallidin, but not bradykinin, peptides were suppressed in patients with severe cardiac failure, suggesting that the activity of the tissue kallikrein-kinin system may be suppressed in this condition. Both angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP) inhibitors increased bradykinin peptide levels. ACE and NEP inhibitors had different effects on kinin peptide levels in blood, urine, and tissues, which may be accounted for by the differential contributions of ACE and NEP to kinin peptide metabolism in the multiple compartments in which kinin peptide generation occurs. Measurement of the levels of individual kinin peptides has given important information about the operation of the kallikrein-kinin system and its role in physiology and disease states.
Asunto(s)
Sistema Calicreína-Quinina/fisiología , Cininas/análisis , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Animales , Bradiquinina/análisis , Bradiquinina/fisiología , Perros , Retroalimentación , Humanos , Calidina/análisis , Calicreínas/análisis , Cininas/sangre , Cininas/efectos de los fármacos , Masculino , Ratas , Ratas Sprague-Dawley , Sistema Renina-Angiotensina/fisiologíaRESUMEN
OBJECTIVE: To evaluate variables of the kininogen-kallikrein-kinin system (KKKS) simultaneously in plasma and saliva of patients with Sjögren's syndrome (SS). METHODS: We studied a group of 20 female patients with SS aged 37-75 years, 7 with primary SS (SS1) and 13 with SS secondary to rheumatoid arthritis (SS2), and 20 healthy individuals. Total kininogen and high and low molecular weight kininogen (HKg and LKg, respectively) levels were evaluated by ELISA. The activity of plasma and tissue kallikreins was determined by enzyme activity on selective chromogenic substrates. RESULTS: The plasma levels of total kininogen, HKg, and LKg, and the activity of plasma kallikrein observed in patients were not significantly different from controls. The tissue kallikrein-like activity in plasma and the active tissue kallikrein in saliva were significantly increased in patients with SS, whereas the total salivary tissue kallikrein activity in patients was not significantly different from controls. The concentration of protein in the saliva of patients was significantly increased, and a positive correlation between salivary protein levels and the active tissue kallikrein was observed. CONCLUSION: Comparisons between the total and the active tissue kallikrein in saliva of patients with SS showed that most of the tissue kallikrein was in its active form. In addition, we observed a concomitant increase of the tissue kallikrein-like activity in plasma. These results suggest increased activation of the KKKS in plasma and saliva of patients with SS.
Asunto(s)
Calicreínas/metabolismo , Quininógenos/sangre , Cininas/sangre , Saliva/metabolismo , Síndrome de Sjögren/sangre , Adulto , Anciano , Artritis Reumatoide/complicaciones , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Persona de Mediana Edad , Proteínas/metabolismo , Saliva/enzimología , Síndrome de Sjögren/enzimología , Síndrome de Sjögren/etiologíaRESUMEN
An acidic proteinase was purified from human kidney cortex. The enzyme showed a molecular mass of 31 kDa by SDS-PAGE, 36 kDa by gel filtration, and isoelectric points of 5.2 and 6.1. The optimum pH for hydrolysis of bovine hemoglobin was about 3.5. Reverse-phase HPLC analysis of the incubation mixture of the enzyme with human plasma showed the presence of an active peptide on rat uterus muscle with the same retention time as the methionyl-lysyl-bradykinin (MLBK) standard. The specific activities were 2.91 micrograms MLBK equivalent mg-1.min-1 at pH 3.5 and 2.15 micrograms MLBK equivalent mg-1.min-1 at pH 6.0. All the enzymatic activities of this human kidney proteinase were inhibited by pepstatin A. Intramolecularly quenched fluorogenic substrates with amino acid sequences of human kininogen were used to determine the cleavage points. On the N-terminal sequences (Abz-Leu-Met-Lys-Arg-Pro-Eddnp and Abz-Met-Ile-Ser-Leu-Met-Lys-Arg-Pro-Eddnp) the cleavage occurred at the Leu-Met linkage, and on the C-terminal sequences (Abz-Phe-Arg-Ser-Ser-Arg-Eddnp and Abz-Phe-Arg-Ser-Ser-Arg-Gln-Eddnp) the cleavage occurred at the Arg-Ser linkage. Abz-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg-Ser-Ser-Arg-Gln-Eddnp++ + was hydrolyzed by the renal acidic proteinase and yielded the peptide Abz-Arg-Pro-Pro-Gly-Phe-Ser-Pro-Phe-Arg (Abz-bradykinin). Kinectic parameters were determined using Abz-Met-Ile-Ser-Leu-Met-Lys-Arg-Pro-Eddnp (K(m) = 0.69 +/- 0.08 microM; Kcat = 0.052 +/- 0.0095 s-1; Kcat/K(m) = 0.075 +/- 0.005 microM-1.s-1) and Abz-Phe-Arg-Ser-Ser-Arg-Gln-Eddnp (K(m) = 1.56 +/- 0.16 microM; Kcat = 0.0048 +/- 0.0001 s-1; Kcat/K(m) = 0.003 +/- 0.0003 microM-1.s-1). Human liver cathepsin D had no activity on C-terminal sequences and human pepsin hydrolyzed them at the Ser-Ser bond. The results suggest that the renal acid proteinase is distinct from human pepsin and human liver cathepsin D and releases MLBK from human kininogen.
Asunto(s)
Ácido Aspártico Endopeptidasas/metabolismo , Calicreínas/metabolismo , Corteza Renal/enzimología , Secuencia de Aminoácidos , Animales , Ácido Aspártico Endopeptidasas/aislamiento & purificación , Catepsina D/metabolismo , Bovinos , Perros , Humanos , Concentración de Iones de Hidrógeno , Calicreínas/aislamiento & purificación , Cinética , Cininas/sangre , Hígado/enzimología , Datos de Secuencia Molecular , Pepsina A/metabolismo , RatasRESUMEN
Using pharmacological preparations suitable for assay of mammalian kinins, it was shown that Bothrops jararaca (Bj) venom and other kininogenases were unable to release kinins from snake plasma. The kallikrein-kinin system presents species-specificity in birds. In order to detect such a specificity in snakes, the effects of Bj venom on snake blood pressure and the effect of incubates of snake plasma with trypsin, on snake blood pressure and snake uterus, were studied. The possibility of activating snake plasma kallikrein with ellagic acid, glass beads or kaolin was also investigated. Whereas plasma of the snakes Waglerophis merremii (Wm) and Crotalus durissus (Cd), were shown to contain factor XII, prekallikrein, kininogen, kininases and to present a low but definite activation rate of the kinin system, the plasmas of Bj, Bothrops mojeni (Bm) and Oxyrophus trigeminus (Ot), yielded only kininogen and kininases. Activation of the system was not even detected by the sensitive substrate Ac-Phe-Arg-Nan (acetyl-phenylalanyl-arginyl-4nitro-anilide), indicating that the plasma of these species does not possess either factor XII and/or prekallikrein. Snake plasma may constitute an interesting model for the study of blood clotting, fibrinolytic and complement systems.
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Calicreínas/sangre , Cininas/sangre , Serpientes/sangre , Animales , Biotransformación/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Columbidae , Venenos de Crotálidos/farmacología , Ácido Elágico/farmacología , Femenino , Vidrio , Antagonistas de los Receptores Histamínicos/farmacología , Humanos , Técnicas In Vitro , Caolín/farmacología , Masculino , Tripsina/farmacología , Útero/efectos de los fármacos , Útero/metabolismoAsunto(s)
Calicreínas/sangre , Cininas/sangre , Postura , Embarazo/sangre , Sistema Renina-Angiotensina , Presión Sanguínea , Diuresis , Femenino , Humanos , Natriuresis , Potasio/sangreRESUMEN
1. Kinin levels began rising on day 3 after infection of cattle with Babesia bovis (= B. argentina) and attained a maximum value of 98% above preinfection levels by day 7. 2. Kininogen levels began falling on day 3 and reached minimum levels of 83% below preinfection levels on day 8. 3. Changes in both kinin and kininogen levels on day 3 coincided with the detection of low levels of parasites, and with a fall in packed cell volume. 4. Plasma kininase levels rose significantly 6 to 9 days after infection. Preparations of lysed and sonicated uninfected and infected red cells contained kininase activity, the respective red cell preparations being 23.9 and 11.4 times more active per mg protein than uninfected red cell preparations. The effect of pH, and the inhibitors disodium edetate, 1,10 phenanthroline and aprotinin on normal and infected plasma and on the various red cell preparations suggested that the rise in plasma kininase levels during infection was probably at least partly due to parasite products. 5. These results are discussed in relation to previous data showing that both kallikrein activation and the onset of hypotension also occur on or about day 3.
Asunto(s)
Babesiosis/sangre , Enfermedades de los Bovinos/sangre , Cininas/sangre , Peptidil-Dipeptidasa A/sangre , Animales , Bioensayo , Bovinos , Eritrocitos/enzimología , Femenino , Quininógenos/sangre , Masculino , Ratas , Útero/enzimologíaRESUMEN
Plasma supernatant in which kallikrein has been activated and removed by glass powder whilst kininogen I (HMW) has been consumed by the activated kallikrein, was used for the preparation of kininogen II. It was purified by chromatography on DEAE-cellulose followed by gel filtration on G-200 Sephadex. The purification of kininogen II was assessed from determinations of the amount of kinin released (expressed as bradykinin) as measured on the isolated guinea pig ileum, using samples incubated with human salivary kallikrein or trypsin. A preparation of kininogen II containing an activity equivalent to 8 microgram Br/mg protein, was obtained. Salivary kallikrein released approximately three times more kinin from the substrate as compared to trypsin.