Changes in plasma kininogen levels induced by cellulose sulphate during pregnancy in the rat

1 Cellulose sulphate (1 mg/kg) produced a 30-40% depletion of plasma kininogen in rats.2 The time course of repletion of kininogen in the plasma was compared in rats in the oestrous and dioestrous stages of the cycle and in 22 day pregnant animals. A partial repletion occurred, 3 h after the cellulose sulphate injection, which was followed by a secondary fall in plasma kininogen. Plasma kininogen values were back to control levels 10 h after the treatment in all groups.3 Treatment of rats from days 19-22 of pregnancy with cellulose sulphate resulted in 40% depletion of plasma kininogen and in prolongation of pre-parturition behaviour.4 It is suggested that the increase which normally occurs in plasma kininogen levels towards the end of pregnancy in the rat may play a role in the process of parturition.     

Some pharmacodynamic properties of carrageenin in the rat

1. Carrageenin oedema is suppressed by pre-treating the rats with cellulose sulphate, a kininogen depleting agent. This inhibition is closely related to the dose of cellulose sulphate and to the time course of kininogen depletion.2. Oedema induced by egg white or by dextran, in which the mediators are histamine and 5-hydroxytryptamine, is quite unaffected by cellulose sulphate treatment.3. Carrageenin injected intravenously lowers the arterial blood pressure of rats. This hypotensive effect is unaffected by histamine antagonists and is abolished by protease inhibitors and thus seems to be due to kinin release from plasma substrates.4. Like cellulose sulphate, carrageenin enhances the esterolytic activity of the blood from treated rats when incubated with benzoyl-arginine ethyl ester.5. The ability of carrageenin to activate the kinin-forming system could account for both its inflammatory and hypotensive effects.     

Fibrinolytic activity evoked in the plasma of the normal and adrenalectomized rat by cellulose sulphate

1. Cellulose sulphate, a kinin-releasing agent, produced fibrinolytic activity in plasma when administered intravenously to the rat but not when added to fresh rat plasma in vitro. The in vivo effect was maximal within 1 min and disappeared within 10-20 minutes. It was retained in plasma taken 1 min after the injection and kept at room temperature for 30 minutes.2. A decrease of anti-fibrinolytic potency measured against urokinase-activated bovine plasmin, was shown to occur in plasma of rats given cellulose sulphate.3. Activated rat plasma lysed heat-denatured fibrin: it probably contains free plasmin as well as plasminogen activator.4. Adrenalectomized rats did not exhibit fibrinolytic activity nor statistically significant benzoyl-arginine ethyl ester-esterase activation in plasma after cellulose sulphate treatment.5. Adrenalectomized rats had significantly increased levels of plasma kininogen, but were normally sensitive to the kininogen-depleting action of cellulose sulphate.6. The increased plasma kininogen of adrenalectomized rats seems to be a consequence of the impairment of the plasminogen activating mechanism.     

Effect of cellulose sulphate on serum complement

Cellulose sulphate 50-600 mug/ml reduces complement titres in human serum. This effect is, in contrast to the clot-promoting and plasma kinin forming action of cellulose sulphate, not mediated by clotting factor XII.     

Mechanism of ionophore A23187 induction of plasma protein leakage and of its inhibition by indomethacin

Calcium ionophore A23187 produced a dose-dependent increase in plasma protein leakage on intradermal injection in rats. Studies with mepyramine and cyproheptadine indicated that histamine and 5-hydroxytryptamine (5-HT) partially contribute to the ionophore action and experiments with compound 48/80 supported these findings. Depletion of plasma kininogen levels with cellulose sulphate administered indomethacin inhibited the ionophore response in a dose-dependent manner. The inhibition was not reversed by intradermally injected prostaglandin E2 (PGE2) in doses up to 50 ng/site, suggesting that PGE2 also may not be an important mediator. It is proposed that the ionophore produces plasma protein leakage by an indirect (through histamine and 5-HT release) and a direct action on vascular endothelial cells and that indomethacin antagonises both actions by inhibiting calcium transport processes.     

Mediators of the inflammation induced in the rat paw by carrageenin

1. The time course of oedema formation in rats caused by injection of carrageenin into the paw was followed for 5.5 hours. Intact or adrenalectomized rats which had previously been injected with ellagic acid or saliva to reduce considerably the concentration of blood kininogens, or with methysergide to antagonize 5-hydroxytryptamine (5-HT) showed a reduced inflammatory response. It was concluded that kinins and 5-HT contributed significantly to oedema formation during this period.2. Mepyramine alone had no effect on oedema formation, but in combination with ellagic acid treatment, with or without methysergide, it caused a reduction suggesting that histamine played a minor role in oedema formation during the first 3 hours.3. Vascular permeability studies indicated that injection of ellagic acid did not interfere with the normal responses in skin to intradermal injections of histamine, 5-HT, bradykinin or compound 48/80. Mepyramine and methysergide, at the doses used in the carrageenin experiments, completely antagonized histamine and 5-HT, respectively, and did not affect the skin responses of bradykinin.4. Treatment in vivo with ellagic acid or rat saliva was equally effective in reducing plasma kininogen concentrations by an amount equivalent to more than 10 times the quantity of substrate 1 measured by Gautvik & Rugstad (1967).5. Rat saliva, but not ellagic acid, lowered complement levels by approximately 20%.     

Inhibition of Carrageenin-Induced Rat Paw Oedema by Substances Causing a Reduction of Kininogen and Prekallikrein in Plasma

The acute, anti-inflammatory effect of bradykinin, ellagic acid, hista-mine, padutin ®, serotonin, trasylol® and trypsin was tested against carrageenin-induced rat paw oedema, and the in vivo effects of the same substances on parameters of the plasma kinin system was also examined. The substances were injected intraperitoneally and oedema was induced half an hour later. Groups of 5 test- and 5 control rats were used, and measurements of initial paw volumes and of volumes after 1, 2 and 3 hours were used for calculating the inhibition values. All the substances tested, except padutin, inhibited the development of oedema and except for padutin and trasylol, caused a fall in total kininogen. Apart from bradykinin and padutin, the substances also reduced the amount of pre-kallikrein. The kininogen fractions activated by rat plasma kallikrein and by rat urine kallikrein were determined in order to calculate the 3 kininogen fractions S1^I, s1^II and S2 (Briseid et al. 1970a). All the substances tested caused a fall in the amount of S1^II and only trypsin in the amount of S1^I, while none of the substances altered the amount of S2. A significant correlation between the effects on factors involved in the plasma kinin system and the anti-oedema effects provides evidence for the presence of a causal relationship.     

Reduced cofactor function of human high molecular weight kininogen induced by rat plasma kallikrein

Plasma kallikrein purified from acetone-activated, plasminogen-free rat plasma yielded in polyacrylamide gel electrophoresis protein bands corresponding to Mr values of 143,000 (main band) and 135,000 (lighter band). After SDS treatment without reduction the protein pattern had changed to two strong bands corresponding to Mr values of 87,000 and 78,000. Gel electrophoresis of kallikrein purified from plasma of rats pretreated with clinical dextran (200 mg/kg intravenously) produced main bands corresponding to Mr values of 120,000-130,000 and 78,000-80,000 for native samples and SDS-treated samples respectively (Johansen & Briseid 1983). Both kinds of kallikrein reduced the capacity of human high molecular weight kininogen to function as a cofactor in the surface-mediated activation of factor XII in a crude plasma preparation. The preparation obtained from plasma of dextran-treated rats was significantly more potent than was the normal kallikrein preparation, both as regards the effect against HMrK, and as an activator of plasminogen.     

Involvement of alpha 2-adrenoceptors in the activation of kininogenesis by clonidine

The effects of clonidine and alpha 2-adrenoceptor blocking agents, yohimbine and tolazoline on kininogen and prekallikrein levels in plasma and on blood pressure were investigated in male Wistar rats. Clonidine (0.5 mg/kg) decreased concentration of kininogen. Yohimbine (3 mg/kg) and tolazoline (5 mg/kg) counteracted this effect of clonidine and increased the kininogen level in plasma. Clonidine did not change the level of prekallikrein, however in rats receiving alpha 2-adrenoceptor blockers alone or together with clonidine kallikrein utilization was reduced, which indicated indirectly that the level of prekallikrein in plasma augmented. Yohimbine and tolazoline in the same doses (3 mg/kg and 5 mg/kg resp.) increased the blood pressure and counteracted the hypotensive action of clonidine, which indicated the presynaptic alpha 2-adrenoceptor blocking effect of the doses used. The data indicate that clonidine-induced activation of kininogenesis as well as its hypotensive effect are counteracted by yohimbine and tolazoline in doses blocking specifically presynaptic alpha 2-adrenoceptors. It can be suggested that alpha 2-adrenoceptors are involved in the kininogenesis-activating effect of clonidine.     

The potentiation of human C1-inhibitor by dextran sulphate is transient in vivo: studies in a rat model

C1-inhibitor (C1-Inh) is an important regulator of inflammatory reactions because it is a potent inhibitor of the contact and complement system. C1-Inh application in inflammatory disease is, however, restricted because of the high doses required. The glycosaminoglycan-like molecule dextran sulphate (DXS) enhances C1-Inh function in vitro. Hence, we investigated whether co-administration with dextran sulphate reduces the amount of C1-Inh required, through enhancement in vivo. C1-Inh potentiation was measured in a newly developed C1s-inactivation assay that is based on activation of C4 by purified C1s. Activated C4 in rat plasma was quantified with a newly developed ELISA. Human C1-Inh (2.5 microM) inhibited C1s in rat plasma 55-fold faster in the presence of dextran sulphate (15 kDa, 5 microM). To study the stability of the complex in vivo, rats were given a mixture of C1-Inh (10 mg/kg) and dextran sulphate (3 mg/kg). C1-Inh activity during 5 h was analyzed ex vivo with the C1s inactivation assay. The noncovalent C1-Inh-dextran sulphate complex resulted in a transient enhancement of the inhibitory capacity of C1-Inh, lasting for 60-90 min. Dextran sulphate did not affect plasma clearance of C1-Inh. We conclude that the enhanced inhibitory capacity of C1-Inh complexed to dextran sulphate is transient in vivo. Hence, co-administration of these compounds seems a feasible approach to achieve short-term inhibition of complement in vivo.     

Effect of boswellic acids on complement in adjuvant— and carrageenan—induced inflammation

Kapil A. Effect of boswellic acids on complement in adjuvant- and carrageenan-induced inflammation. Inflammopharmacology. 1994;2:361-367. The in-vivo effects of non-steroidal anti-inflammatory agents on the host immune system are still poorly understood. However, through inhibition of complement, boswellic acids (BA) exhibit adjuvant-induced and carrageenan-induced anti-inflammatory properties. The present work was aimed at evaluating the influence of BA on complement-related inflammation in the experimental models of inflammation. In adjuvant-induced arthritis and carrageenan-induced paw oedema in rats, BA were found to possess significant anti-inflammatory and complement-inhibitory activities. The intraperitoneal injection of BA (100 mg/kg twice a day), before and after FCA challenge and thereafter repeated for several days, significantly reduced foot pad thickness of experimental animal models and simultaneously also reduced complement activity. It also showed marked reduction in complement levels and inflammatory effects on carrageenan-induced paw oedema in rats when injected intraperitoneally (100 mg/kg twice a day).     

卡介菌多糖核酸的抗炎和抗过敏作用

目的　研究卡介菌多糖核酸 (BCG PSN)的抗炎、抗过敏作用。方法　观察对磷酸组胺所致豚鼠皮肤瘙痒的影响 ;采用二甲苯所致小鼠耳廓肿胀及角叉菜胶所致大鼠足跖肿胀实验观察抗炎作用 ;以 2 ,4 二硝基氟苯所致小鼠皮肤迟发型变态反应、大鼠同种被动皮肤过敏反应及小鼠异种被动皮肤过敏反应 ,探讨抗过敏作用。结果　豚鼠隔日肌内注射BCG PSN(0 1,0 2 ,0 4mg·kg-1) 3wk ,对磷酸组胺所致皮肤瘙痒无明显影响。小鼠隔日肌内注射BCG PSN(0 15 ,0 30 ,0 6 0mg·kg-1) 3wk ,可剂量依赖性地抑制二甲苯所致耳廓肿胀和耳异种被动皮肤过敏反应 ,高剂量时也可显著抑制 2 ,4 二硝基氟苯诱导的迟发型变态反应。大鼠隔日肌内注射BCG PSN(0 1,0 2 ,0 4mg·kg-1) 3wk ,可剂量依赖性地抑制角叉菜胶所致足跖肿胀和同种被动皮肤过敏反应。收稿日期 :2 0 0 3 -12 -2 4,修回日期 :2 0 0 4-0 2 -12作者简介 :刘桂珍 ( 1965 -) ,女 ,主管实验师 ,研究方向 :心血管药理学。Tel:0 73 1 2 3 5 5 0 77;胡长平 ( 1969-) ,男 ,博士 ,副教授 ,通迅作者 ,研究方向 :心血管药理学 ,Tel:0 73 1 2 3 5 5 0 77,E mail:huchangping2 0 0 1@yahoo .com .cn结论　BCG PSN对急性炎症、速发型变态反应和迟发型变态反应具有抑制作用。     

Decreased formation of ethoxyacetic acid from ethylene glycol monoethyl ether and reduced atrophy of testes in male rats upon combined administration with toluene and xylene

Male painters are commonly exposed to ethylene glycol monoethyl ether (EGE), a well known reproductive toxic agent causing testicular atrophy, in the form of solvent mixture containing toluene (TOL) and xylene (XYL). This study was carried out to determine the effect of exposing male rats to solvent mixture containing TOL and XYL on the EGE (200 mg/kg) on testicular atrophy and production of toxic metabolite, ethoxyacetic acid (EAA) from EGE. Compared to the extent of testes atrophy observed upon EGE administration alone, the combined administration of EGE (200 mg/kg) with TOL (250 mg/kg) and XYL (500 mg/kg) for 4 weeks has reduced the extent of testes atrophy by 25%. The combined administration delayed the time for appearance of the highest plasma concentration (t(max)) of EAA from 3 to 6 h and also decreased the highest concentration (Cmax) as well as the total amount of plasma EAA (AUC(0-18 h)) by 45 and 29%, respectively. This explained the diminished testicular atrophy in male rats observed when EGE was administered in a solvent mixture containing TOL and XYL. This study suggested that testicular toxicity observed in male painters caused by EGE may be decreased when they are exposed to EGE in the form of solvent mixture containing TOL and XYL.     

Neutralization of the oedematogenic activity of Bothrops jararaca venom on the mouse paw by an antibothropic fraction isolated from opossum (Didelphis marsupialis) serum.

The pharmacological modulation of mice paw oedema produced by Bothrops jararaca venom (BJV) has been studied. Intraplantar injection of BJV (1-30 micrograms/paw) produced a dose- and time-related oedema, which was maximal 30 min after injection, reduced gradually thereafter and disappeared over 48 h. BJV heated at 100 degrees C for 5 or 15 min blocked local hemorrhage and caused partial inhibition of its oedematogenic activity. The BJV oedema was not inhibited by the anti-histamine meclizine, the inhibitor of histamine and serotonin, cyproheptadine, PAF-acether antagonist WEB 2170 or by the anti-leukotrienes C4/D4, LY 171883. Dexamethasone, aspirin, indomethacin, and the dual cyclooxygenase and lipoxygenase inhibitor BW 755C inhibited BJV-induced oedema indicating that arachidonic acid metabolism products via the cyclooxygenase pathway participate in its genesis and/or maintenance. The antibothropic fraction (ABF) (25-200 micrograms/paw) isolated from Didelphis marsupialis serum neutralized the oedema induced by the venom with and without heating, the hemorrhage induced by BJV and partially blocked the oedema induced by bradykinin and by cellulose sulphate. The oedema produced by histamine, serotonin, PAF-acether or leukotriene C4 was not inhibited.     

Altered cardiac tissue and plasma kininogen levels in hypertensive and diabetic rats

The present investigation was aimed at evaluating the cardiac and total plasma kininogen levels, as well as LVWT in hypertensive and diabetic rats. STZ-induced diabetes produced a significant (P < 0.001) rise in mean arterial blood pressure (BP). The LVWT increased (P < 0.001) in SHR with and without diabetes) and diabetic WKYR. The cardiac tissue, as well as total plasma kininogen levels fell significantly (P < 0.001) in diabetic WKYR and SHR with and without diabetes compared to the control WKYR. These findings suggest that reduced kininogen levels may indicate a deficiency in kinin generation in the heart and in the peripheral circulation in diabetic and hypertensive rats. This effect may contribute to the development of LVH.     

Coordination of copper with aspirin improves its anti-inflammatory activity

Anti-inflammatory activity of copper aspirinate administered orally was investigated in several models of inflammation. The results showed that copper aspirinate 50 mg/kg markedly inhibited inflammatory processes of either ear swelling induced by xylene in mice or turpentine-elicited air pouch granuloma in rats, with an activity equal to that of aspirin 200 mg/kg. Copper aspirinate 25 mg/kg significantly suppressed acute paw oedema produced by injecting 1% carrageenan, with an action time lasting over 6 h; and that copper aspirinate 100 mg/kg decreased the content of protein in the inflammatory exudate from rats with air pouch synovitis caused by acetic acid. It is suggested that, compared with aspirin, copper aspirinate showed a similar anti-inflammatory spectrum but greater anti-inflammatory activity. Zhiqiang S, Lei WY, Li L, Chen ZH, Liu WP. Coordination of copper with aspirin improves its antiinflammatory activity. Inflammopharmacology 1998;6:357-362     

Hypertensive drugs and plasma kinins in rats

The influence of phenylephrine (PHE), methoxamine (MET) and ephedrine (EPH) on kininogen and prekallikrein level in plasma was investigated in male Wistar rats. Simultaneously the effect of these drugs on blood pressure was monitored. No changes in kininogenesis were observed during the hypertension period (2 h after ip injection). The significant decrease in kininogen level (by 20-30%) was found 4 h after PHE (5 mg/kg) or EPH (40 mg/kg) and 4-12 h after MET (40 mg/kg) injection. The reduction of kallikrein utilization, indicating an increase in prekallikrein level in plasma, was noted only after PHE (by 34%) or MET (by 44%) administration. Phentolamine (REG) in a dose of 20 mg/kg, which counteracted the hypertensive effect of investigated drugs, abolished the influence of these drugs on kininogen level. The results indicate that the hypertension induced by alpha-adrenoceptor agonists evokes the delayed activation of kininogenesis parallel to the secondary decrease in blood pressure. Such a reaction of kinin system seems to be related to primary alpha-adrenoceptor stimulation, not to the direct influence of hypertensive drugs on kinin system in rat plasma.     

Rat paw edema induced by trimucase II, a kinin-releasing enzyme from Trimeresurus mucrosquamatus venom

Trimucase II, a proteolytic enzyme isolated from Trimeresurus mucrosquamatus venom, caused rat hind-paw edema dose dependently. Captopril potentiated significantly, while pretreatment with cellulose sulfate suppressed the trimucase II-induced edematous response. Pretreatment with diphenhydramine and methysergide reduced by 42 and 46% the edema induced by trimucase II and kallikrein, respectively. The residual response was significantly further depressed by [Thi5,8,D-Phe7]bradykinin and trasylol. Kinin generation by trimucase II was also found in vitro from plasma and was concentration- and time-dependent. Kinin formation was inhibited by soybean trypsin inhibitor, trasylol and endogenous kininase. The kinins released were destroyed by chymotrypsin. Unlike cellulose sulfate, trimucase II caused kinin formation from Factor XII-deficient and prekallikrein-deficient plasma but not from high molecular weight kininogen-deficient plasma. These data indicate that, in addition to the mediators released from mast cells, kinins have an important role in the edema caused by trimucase II, and that kinins are released from plasma, probably due to direct activation of kininogen.     

THE ACTION OF ASPIRIN ON PLASMA KININOGEN AND OTHER PLASMA PROTEINS IN RHEUMATOID PATIENTS: RELATIONSHIP TO DISEASE ACTIVITY

1. When six female seropositive rheumatoid patients were given placebo therapy for 48 h, their mean plasma kininogen level, 9.2 ± 0.7 μg bradykinin equivalents (bk eq) per ml, was found to be 59% greater than that of a group of eight healthy female volunteers (5.8 ± 0.5 μg/ml). 2. When the rheumatoid patients received aspirin therapy for 1 week, their mean plasma kininogen concentration fell by 31% to 6.3 ± 0.8 μg Bk eq/ml. This was accompanied by a 20.4% fall in mean plasma α₂-globuKn level. Haematocrit and total plasma protein were not significantly altered (P > 0.05). 3. The fall in kininogen was very rapid, the main reduction occurring within the first hour. 4. Aspirin therapy greatly reduced the pain assessments but had no effect on plasma concentrations of IgG, IgA, IgM, complement component C3, nor on ESR, haemoglobin, leucocyte count, nor ring size. Left hand grip strength was increased while right hand grip strength was unchanged. 5. The action of aspirin on plasma kininogen and α₂-globulin was similar to that of indomethacin. Plasma kininogen has been considered to be an acute phase reactant. The possible diagnostic value of plasma kininogen estimation is discussed.