Analysis of the mechanisms involved in the inflammatory response induced by des-Arg9-bradykinin in the rat pleural cavity

OBJECTIVE

The present study investigates some of the mechanisms underlying the inflammatory responses caused by the selective B1 kinin receptor agonist, des-Arg9-bradykinin (des-Arg9-BK), in the rat pleural cavity.

MATERIAL

Male Wistar rats were used (N = 4-10 per group).

TREATMENT

A fixed volume (100 microl) of PBS or des-Arg9-BK (10-60 nmol) was injected into the rat pleural cavity. Animals were treated with the B1 des-Arg9[Leu8]-BK (60 nmol/cav.) and R715 (65 nmol/cav.), B2 HOE 140 (3 nmol/cav.), NK1 FK888 (1 nmol/cav.), NK2 SR 48968 (20 nmol/cav) or NK3 SR142801 (10 nmol/cav.) receptor antagonists, or with either cyproheptadine (40 mg/kg, i.p.) or compound 48/80 (0.6 mg/kg, i.p., twice a day/3 days, 1.2 mg/kg/4th day).

RESULTS

des-Arg9-BK (30 nmol/cavity) induced a time-dependent leukocyte migration. The increase in total leukocytes was not significantly reduced by the treatment with any of the B1, B2, NK1, NK2 or NK3 receptor antagonists. Treatment of animals with cyproheptadine or with compound 48/80 markedly inhibited des-Arg9-BK-induced cell migration (77 +/- 7 and 82 +/- 4%, respectively).

CONCLUSION

These findings suggest that inflammatory responses caused by the B1 agonist des-Arg9-BK in the rat pleural cavity are mediated by a receptor-independent mechanism, being largely dependent on the activation of resident mast cells and release of histamine and/or serotonin.

Inflammatory pain: kinins and antagonists

This short review focuses on the most recent findings in the rapidly expanding field of kinin research. Through a series of recent publications, the crucial relevance of this group of peptides as mediators of inflammatory pain is becoming increasingly evident. On the strength of this idea, kinins have been implicated as algogen peptides produced in response to noxious stimuli. The importance of kinins has been elucidated by different pharmacological and molecular approaches. Special attention has been given to studies with selective kinin antagonists, as well as to the use of receptor gene deletion technology. The gathering of results has demonstrated that both B(1) and B(2) receptors seem to exert a meaningful role during nociceptive responses, the B(1) receptor being most relevant in the chronic stages of inflammatory pain. It is hoped that new effective and useful therapeutic agents, mainly B(1) kinin selective receptor antagonists, might soon be available.

S-TREE: self-organizing trees for data clustering and online vector quantization

This paper introduces S-TREE (Self-Organizing Tree), a family of models that use unsupervised learning to construct hierarchical representations of data and online tree-structured vector quantizers. The S-TREE1 model, which features a new tree-building algorithm, can be implemented with various cost functions. An alternative implementation, S-TREE2, which uses a new double-path search procedure, is also developed. The performance of the S-TREE algorithms is illustrated with data clustering and vector quantization examples, including a Gauss-Markov source benchmark and an image compression application. S-TREE performance on these tasks is compared with the standard tree-structured vector quantizer (TSVQ) and the generalized Lloyd algorithm (GLA). The image reconstruction quality with S-TREE2 approaches that of GLA while taking less than 10% of computer time. S-TREE1 and S-TREE2 also compare favorably with the standard TSVQ in both the time needed to create the codebook and the quality of image reconstruction.

Genetic imbalances in 26 cases of penile squamous cell carcinoma

To obtain more information on chromosomal changes in the up-to-now poorly studied tumor class of penile squamous cell carcinoma (SCC), we performed a comparative genomic hybridization study of 26 cases of this rare tumor. DNA sequence copy number alterations (CNAs) very similar to those detected in other SCC types, such as oral and esophageal SCC, were noted. The most common copy number gains were found in 8q24, 16p11-12, 20q11-13, 22q, 19q13, and 5p15, and the most common deletions were detected in 13q21-22, 4q21-32, and along the X chromosome. Classifying the patients according to the number of CNAs showed a possible correlation with clinical outcome.

Changes in paw oedema triggered via bradykinin B(1) and B(2) receptors in streptozotocin-diabetic rats

The present study investigated hind paw oedema mediated by bradykinin B(1) and B(2) receptors in streptozotocin-diabetic rats. Paw oedema induced by intraplantar (i.pl.) injection of bradykinin or the selective bradykinin B(2) receptor agonist, Tyrosine(8)-bradykinin ([Tyr(8)]bradykinin) (both 3 nmol/paw), was significantly reduced at 4 weeks after streptozotocin treatment (34 +/- 8% and 40 +/- 7%). At 6 weeks after streptozotocin, when paw oedema caused by substance P or prostaglandin E(2) (both 10 nmol/paw) was unchanged, inhibition of bradykinin B(2) receptor-mediated oedema was maximal (66 +/- 6% and 72 +/ -2%, for bradykinin and [Tyr(8)]bradykinin, respectively). The selective bradykinin B(1) receptor agonist, [des-Arg(9)]bradykinin (100 nmol/paw), induced only slight paw oedema in non-diabetic controls. Responses to [des-Arg(9)]bradykinin were markedly enhanced 8 weeks after streptozotocin (from 0.09 +/- 0.01 to 0.38 +/- 0.05 ml), less so at 10 weeks (0.22 +/- 0.03 ml), and returning to basal values at 12 weeks (0.11 +/- 0.03 ml). Treatment with insulin protamine zinc (1-3 U/day/7 weeks, s.c.) did not reverse the inhibition of responses to [Tyr(8)]bradykinin or the potentiation of responses to [des-Arg(9)]bradykinin seen at 8 weeks. Thus, streptozotocin-induced diabetes induces long-lasting alterations in oedematogenic responsiveness to kinins in the rat, characterized by marked reduction of oedema involving activation of bradykinin B(2) receptors, associated with enhancement of bradykinin B(1) receptor-mediated oedema.

Clinical implications of natural killer cytotoxicity in patients with squamous cell carcinoma of the penis

Impairment of natural cytotoxicity mediated by natural killer (NK) cells may play a role in the pathogenesis of penile carcinoma. The aim of this study was to examine the NK activity profile and its prognostic significance in patients with squamous cell carcinoma of the penis. The NK activity was measured in peripheral blood mononuclear cells (PBMCs) from 39 patients diagnosed histologically as having invasive squamous cell penile carcinoma and 4 patients with verrucous carcinoma of the penis. Of 39 patients with invasive squamous cell carcinoma, 4 had undergone previous penile amputation. According to the prognosis, the patients with invasive squamous cell carcinoma were divided into two groups: with metastasis and without metastasis. The patients were evaluated in relation to clinicopathologic variables using univariate analyses. NK cell activity was significantly decreased in all patients with penile carcinoma when compared with the control groups (p < 0.0001). There was no statistically significant difference between the groups with and without metastasis. We conclude that there is a decrease in NK activity in PBMCs from patients with penile carcinoma and that the presence of advanced disease or metastatic involvement is not responsible for this reduction.

Determination of telomerase activity in squamous cell carcinoma of the penis

Telomerase activity was studied in 51 penile carcinomas, and detected in all samples from 3 patients with verrucous carcinoma, in 85.4% (41/48) of invasive carcinomas, in 81.8% (9/11) of adjacent non-cancerous skin and in 80% (8/10) of adjacent non-cancerous corpus cavernosum. All skin and corpus cavernosum samples from patients with prostatic carcinoma were found to be telomerase negative. Our results indicate a correlation between frequency of telomerase activity and grade of penile carcinoma. The finding of telomerase activity in skin and corpus cavernosum samples adjacent to tumor suggests that unidentified local factors may modulate telomerase activity in normal tissues.

Neurokinin mediation of edema and inflammation

The aim of this article is to furnish a brief review of the role played by neurokinins in the inflammatory process. Further attention is given to the mechanisms, as well as to the receptor subtypes involved in neurokinin-mediated inflammation, in an attempt to clarify the participation of neurokinins in different models of acute and chronic inflammation. The involvement of SP, NKA and NKB is also examined in relation to the major signs of inflammation, including edema formation, protein plasma extravasation and vasodilatation. Finally, we provide a general overview on the potential clinical applications of neurokinin antagonists, along with the involvement of neurokinins in human diseases.

[Detection of antiplatelet antibodies. The first one hundred samples studied]

Two types of platelet alloantigens are considered: type I, which refers to platelet alloantigens shared by platelets and other cells; and type II, which comprises the platelet-specific alloantigens. The Human Platelet Alloantigens (HPA) System consists of five diallelic alloantigens and eleven low frequency antigens. According to serological antigen capture assays, immunochemical methods and studies of Molecular Genetics, the glycoproteins (GP) of platelet membrane that are most frequently associated with antibodies are GPIIb-IIIa, GPIb-IX and GPIa-IIa. It is possible to detect platelet antibodies using different laboratory methods. Our experience was restricted to a solid phase system. In this method we used the indirect technique for the screening of alloantibodies and the direct technique for the detection of autoantibodies. The procedure with chloroquine solution was performed in order to differentiate between the presence of HLA and non-HLA platelet specific antibodies. Our comments are based on results obtained in a hundred samples tested throughout a period of eleven months and we briefly review the clinical features related to the diagnosis of autoimmune and alloimmune thrombocytopenia, drug-induced thrombocytopenia and other different factors of platelet destruction. The concepts of transfusional practice applied to emergency situations, platelet refractoriness strategy and the comprehensive management of patients are approached in this work.

The role of sensorial neuropeptides in the edematogenic responses mediated by B(1) agonist des-Arg(9)-BK in rats pre-treated with LPS

In the present study we have investigated some of the mechanisms underlying B(1) kinin receptor-induced paw edema formation in rats that had been treated with LPS, paying special attention to the involvement of neurogenic inflammation. Intradermal (i.d.) injection of the B(1) receptor agonist des-Arg(9)-BK (100 nmol/paw) resulted in a marked increase in paw volume in animals pre-treated with LPS (0.40+/-0.06 ml). The co-injection of the selective NK(1) FK888 (1 nmol/paw) or NK(2) SR 48968 (3 nmol/paw) receptor antagonists resulted in a significant inhibition of the edema induced by des-Arg(9)-BK (30+/-4 and 25+/-7%, respectively). The NK(3) SR 142801 (3 nmol/paw) antagonist did not demonstrate any significant effect on B(1) receptor-mediated paw edema. The edema induced by des-Arg(9)-BK was also significantly inhibited (33+/-5%) by the co-injection of the CGRP-receptor antagonist CGRP 8-37 (1 nmol/paw) or by treatment of animals with capsaicin (50 mgkg(-1), s.c., 48 h, prior) (45+/-4%). The pre-treatment of animals with methysergide or with mianserin, 5-HT(1) and 5HT(2) antagonists, respectively (both 10 mgkg(-1), i.p. 30 min), resulted in a significant reduction of the edema mediated by B(1) receptors (23+/-5 and 20+/-3%, respectively). In addition, compound 48/80 (12 microg/paw, 24 h) significantly reduced des-Arg(9)-induced paw edema in rats pre-treated with LPS (23+/-3%), while the treatment of animals with the H(1) receptor antagonist pyrilamine (10 mgkg(-1), i.p., 30 min) failed to affect the edematogenic responses involving B(1) receptors. Finally, the co-injection of NOS inhibitors L-NAME (100 nmol/paw) or 7-NINA (10 nmol/paw) did not affect the rat paw edema caused by des-Arg(9)-BK, whereas they significantly inhibited BK-induced paw edema. Jointly, the results of the present study show that the edematogenic response mediated by the activation of B(1) receptors, in animals pre-treated with LPS, involves the release of tachykinins and CGRP, as well as serotonin, while NO and histamine seem not to be involved. Therefore, these data further support the notion that B(1) receptors have an important role in modulating the inflammatory processes.

Receptor subtypes involved in tachykinin-mediated edema formation

Intradermal (ID) injection of the natural tachykinins substance P (SP), neurokinin A (NKA), and neurokinin B (NKB) (0.3-30 nmol) resulted in a marked and dose-related rat paw edema, with mean ED50 values of 2.68 nmol, 1.17 nmol, and 0.80 nmol, respectively. The ID injection of the selective NK1, SP methyl-ester (1-30 nmol), NK2, [beta-Ala8]-neurokinin A4-10) (beta-Ala, 0.3-30 nmol), or NK3, senktide (1-10 nmol) agonists, caused extensive edema formation with mean ED50s of 0.48 nmol, 0.41 nmol, and 0.18 nmol, respectively. The ID injection of the selective NK1 antagonist FK888 (0.1-3 nmol) produced marked inhibition (94%, 52%, and 66%, respectively) of rat paw edema induced by SP, NKA, or SP methyl-ester. The ID co-injection of the NK2 receptor antagonist SR 48968 elicited a graded inhibition (52%, 67%, and 35%, respectively) of rat paw edema induced by NKA, beta-Ala and, to a lesser extent, the edema caused by SP. Finally, the ID co-injection of the NK, receptor antagonist SR 142801 significantly inhibited (53%, 76%, 53%, and 100%, respectively) the edema formation caused by NKB and NKA or by SP and senktide. Together, the data of the present study suggest that tachykinin-mediated rat paw edema depends on the activation of NK1, NK2 and NK3 receptor subtypes, with apparent major involvement of NK1 receptors subtypes.

Anti-hyperalgesic properties of the extract and of the main sesquiterpene polygodial isolated from the barks of Drymis winteri (Winteraceae)

This study analyses the anti-hyperalgesic properties of the hydroalcoholic extract (HE) and the sesquiterpene polygodial isolated from the barks of Drymis winteri (Winteraceae). The HE (10 to 60 mg kg(-1), i.p. or 100 to 600 mg kg(-1), p.o.), 4 h prior, produced significant inhibition of abdominal constrictions caused by i.p. injection of acetic acid, kaolin and zymosan in mice. The mean ID50s were: 21.4, 33.7 and 36.6 mg kg(-1); 173.0, 123.0 and 366.0 mg kg(-1), by i.p. and by oral route, respectively. This effect lasted for up to 8 h. The HE at the same range of doses produced dose-related inhibition of both phases of the formalin-induced licking. The calculated mean ID50s values for the early phase were: 26.1 and 43.0 mg kg(-1), while for the late phase they were 7.3 and 72.7 mg kg(-1), respectively, when given by i.p. and by oral route. The HE (10 to 60 mg kg(-1), i.p. or 25 to 200 mg kg(-1), p.o.), 4 h prior, produced significant inhibition of capsaicin-induced neurogenic pain with mean ID50 values of 18.0 and 68.0 mg kg(-1), respectively. The HE (3 to 100 mg kg(-1), p.o., 1 h) inhibited in a graded manner, the hyperalgesia induced by bradykinin (3 nmol/paw) or substance P (10 nmol/paw) in rat paw, with mean ED50 values of 54.5 and 53.7 mg kg(-1), respectively. However, the HE did not affect the hyperalgesia induced by carrageenan or PGE2. When assessed in the hot-plate test, the HE (200 mg kg(-1), p.o.) was inactive. Naloxone (1 mg kg(-1), i.p.) significantly reversed the antinociceptive effects caused by either morphine (5 mg kg(-1), s.c.) or by HE (60 mg kg(-1), i.p.). Polygodial (0.1 to 10 mg kg(-1), i.p.) produced significant inhibition of acetic acid, kaolin and zymosan-induced writhing in mice, being about 14 to 27-fold more potent than the HE at the ID50 level. Together these data provide support for a long-lasting anti-hyperalgesic property for the active principle(s) present in the barks of D. winteri when assessed in several models of inflammatory or neurogenic pain. Its actions involve, at least in part, an interaction with opioid pathway through a naloxone-sensitive mechanism, seeming not to be related with a non-specific peripheral or central depressant actions. Finally, the sesquiterpene polygodial isolated from this plant, appears to be mainly responsible for the anti-hyperalgesic properties of the extract.

Modulation of kinin B1 but not B2 receptors-mediated rat paw edema by IL-1beta and TNFalpha

The modulatory effects of IL-1beta and TNF alpha on the rat paw edema induced by B1 agonists have been analyzed. In naive rats, i.d. injection of B1 agonists, des-Arg9-bradykinin and des-Arg10-kallidin (up to 300 nmol), causes a minimal increase in paw volume, while the B2 agonist tyrosine8-bradykinin (0.3-10 nmol) induces graded paw edema. The injection of des-Arg9-bradykinin (10-100) nmol or des-Arg10-kallidin (1-100 nmol), in paws pre-treated with IL-1beta or TNF alpha (both 5 ng/paw; 60 and 30 min prior, respectively), caused a graded edema formation. The edemas induced by des-Arg9-bradykinin (100 nmol) were evident at 15 min, reaching the maximum 60 and 30 min after treatment with IL-1beta (0.64 +/- 0.06 ml) or TNF alpha (0.47 +/- 0.05 ml), respectively, being reduced at 360 min. The B1 antagonist des-Arg9-NPC 17731 (1-30 nmol), but not the B2 antagonist Hoe 140 (10 nmol), produced marked inhibition of des-Arg9-bradykinin-induced paw edema. Dexamethasone (0.5 mg/kg, s.c., 4 h) or cycloheximide (1.5 mg/kg, s.c., 6 h) significantly prevented the edema caused by des-Arg9-bradykinin (100 nmol) in rats treated with IL-1beta (81 +/- 5% and 59 +/- 3%) or TNF alpha (78 +/- 4% and 43 +/- 2%). Indomethacin (2 mg/kg, i.p.) or meloxicam (3 mg/kg, i.p.), 1 h prior, significantly reduced the edema induced by des-Arg9-bradykinin (100 nmol) in IL-1beta (40 +/- 6% and 69 +/- 8%) or TNF alpha (43 +/- 3% and 53 +/- 9%) treated rats. It is suggested that i.d. injection of the IL-1beta or TNF alpha, produced up-regulation of B1 receptor-mediated paw edema, being this effect sensitive to dexamethasone and cycloheximide and to cyclo-oxygenase pathway.

Anti-allergic effects and oedema inhibition caused by the extract of Drymis winteri

OBJECTIVE

To study the acute anti-inflammatory and anti-allergic properties of an extract of D. winteri.

MATERIAL AND METHODS

Paw oedema induced in rats with various stimuli and anaphylactic shock in mice.

RESULTS

The hydroalcoholic extract (HE) of D. winteri (Winteraceae) (30 to 100 mg/kg, p.o., 1 h prior) inhibited carrageenan (300 micrograms/paw) and dextran (100 micrograms/paw)-induced paw oedema formation in a dose-dependent manner, with mean ID50 values of 49 and < 30 mg/kg, respectively. The HE of D. winteri (30 to 100 mg/kg) also inhibited paw oedema induced by bradykinin (BK) (3 nmol), substance P (SP) (10 nmol) and PAF-acether (PAF) (10 nmol), in a dose-dependent manner, with mean ID50 values of 56, 63, and 58 mg/kg, respectively. However, the HE inhibited the rat paw oedema induced by prostaglandin E2 (PGE2) (10 nmol) (29 +/- 7 and 33 +/- 2% at 60 and 240 min) to a smaller extent, and had no effect on oedema elicited by histamine (100 nmol). In adrenalectomized animals, the inhibition by the HE of D. winteri (100 mg/kg, p.o., 1 h prior) of BK-elicited oedema (3 nmol/paw) was significantly smaller when compared with that observed in control animals. When assessed in rats actively sensitised to ovalbumin (OVO), the oedema caused by OVO (6 micrograms/paw) was significantly inhibited by HE of D. winteri (30 to 100 mg/kg, p.o.), with a mean ID50 of about 65 mg/kg. The HE of D. winteri (100 and 200 mg/kg, p.o.) significantly increased survival rate when assessed in anaphylactic shock in mice actively sensitised to the antigen. The protective effect was long-lasting, being observed for up to 15 h. Dexamethasone, used as positive control (0.5, 1 and 2 mg/kg) produced a long-lasting (up to 24 h) increase in the survival rate of the animals.

CONCLUSIONS

These results confirm and extend our previous studies, and demonstrate the clear oral anti-inflammatory and anti-allergic properties of the active principle(s) present in the barks of D. winteri, thus confirming its reported medicinal use in folk medicine for the management of airway diseases.

The role of B1 and B2 kinin receptors in oedema formation after long-term treatment with Mycobacterium bovis bacillus Calmette-Guérin (BCG)

1. The present study was designed to investigate the influence of long-term systemic treatment with Mycobacterium bovis bacillus Calmette-Guérin (BCG, 1 dose per animal, containing 6 x 10(4) colony-forming-units (CFu), 5 to 75 days beforehand) on oedema formation induced by intradermal injection of B1 and B2 selective agonists. The interaction between the B1 agonist des-Arg9-bradykinin and bradykinin was also investigated. 2. Intradermal injection (i.d.) of the B2 selective agonist tyrosine8-bradykinin (1-10 nmol) in naive (saline pretreated) animals, or in animals that had received BCG (30 days beforehand), caused dose-related and very similar oedema formation (ED50; 1.1 and 1.0 nmol/paw, respectively). I.d. injection of the selective B1 agonists des-Arg9-bradykinin (100 nmol) or des-Arg10-kallidin in naive animals caused very little paw oedema (0.04 +/- 0.06 and 0.07 +/- 0.02 ml, respectively, n = 5). However, i.d. injection of des-Arg9-bradykinin (10-300 nmol) or des-Arg10-kallidin (3-100 nmol) in animals pretreated with BCG, 30 days previously, resulted in dose-related and marked oedema formation, with mean ED50 values of 20.1 and 5.5 nmol/paw, respectively. 3. Oedema caused by i.d. injection of des-Arg9-bradykinin (100 nmol/paw) in rats pretreated with BCG was evident 5 days after treatment, reaching the maximum 30 days later, remaining stable for up to 45 days, and reduced markedly at 75 days. 4. The i.d. co-injection of the selective B1 antagonists des-Arg9[Leu8]-bradykinin (200 nmol), des-Arg10[Leu9]-bradykinin (30 nmol) and des-Arg9-NPC 17731 (30 nmol) significantly (18 +/- 3, 34 +/- 2 and 56 +/- 4%, respectively) prevented the paw oedema caused by i.d. injection of des-Arg9-bradykinin (100 nmol) in rats treated with BCG. These effects were selective, because the i.d. injection of the B1 selective antagonist des-Arg10[Leu9]-kallidin (30 nmol), at the same dose that consistently antagonized des-Arg9-bradykinin (100 nmol)-mediated paw oedema, had no significant effect against tyrosine8-bradykinin (3 nmol)-induced oedema in animals that had been treated previously with BCG. On the other hand, the i.d. co-injection of the selective B2 antagonist, Hoe 140 (10 nmol) at a dose which markedly inhibited tyrosine8-bradykinin (3 nmol)-induced oedema by 55 +/- 4%, did not significantly affect des-Arg9-bradykinin-induced paw oedema in animals pretreated with BCG. 5. Treatment of animals with dexamethasone (0.5 mg kg-1, s.c.) every 24 h, from day 0 to day 30, inhibited significantly (67 +/- 4%) the oedema caused by des-Arg9-bradykinin (100 nmol), but did not affect the paw oedema caused by tyrosine8-bradykinin (3 nmol) in animals pretreated with BCG. 6. Indomethacin (2 mg kg-1, i.p.), administered 1 h before experiments, significantly inhibited des-Arg9-bradykinin (100 nmol)-induced oedema formation, and, to a lesser extent, the paw oedema caused by tyrosine8-bradykinin (3 nmol) (44 +/- 4 and 20 +/- 4%, respectively). 7. These findings show that the long-term systemic treatment of rats with BCG promoted a time-dependent and consistent paw oedema formation to B1 agonists, des-Arg9-bradykinin and des-Arg10-kallidin, leaving responses to the B2 agonist tyrosine8-bradykinin unaffected. The upregulation of B1 receptors after BCG treatment was inhibited by dexamethasone, suggesting the possible involvement of de novo protein synthesis. Finally, our results also show that in BCG-treated animals, the B1 agonist des-Arg9-bradykinin interacts in a synergistic manner with bradykinin. Therefore, both B1 and B2 kinin receptors appear to play a relevant role in modulating chronic inflammatory processes.

Upregulation of B1 receptor mediating des-Arg9-BK-induced rat paw oedema by systemic treatment with bacterial endotoxin

1. The effect of pretreatment with bacterial endotoxin (LPS, 10 micrograms, i.v., 24 h) on the bradykinin B1 and B2 receptor-induced oedema in the rat paw, and the interaction of B1-mediated responses with other inflammatory mediators, was investigated. 2. Intraplantar (i.pl.) injection of the selective B1 agonist, des-Arg9-BK (DABK, 100 nmol) in naive animals pretreated with the angiotensin converting enzyme inhibitor, captopril caused a small increase in paw volume (0.04 +/- 0.003 ml, mean +/- s.e. mean, n = 6), while the B2-selective agonist, tyrosine8-bradykinin (T-BK, 3 nmol) induced marked oedema (0.36 +/- 0.02 ml). However, i.pl. injection of DABK (3-300 nmol) in rats pretreated with LPS (24 h beforehand) resulted in a marked dose- and time-related increase in paw volume, with mean ED50 of 24.1 nmol. In contrast, oedema caused by T-BK (3 nmol) was reduced by 79 +/- 4% in animals treated with LPS when compared with naive animals. 3. Oedema caused by prostaglandin E2 (PGE2, 10 nmol) was unaffected by LPS treatment, while oedema induced by histamine (100 nmol), 5-hydroxytryptamine (5-HT, 10 nmol) and substance P (SP, 3 nmol) was reduced (P < 0.05). 4. The selective B1 antagonist, des-Arg9[Leu8]-BK (100-300 nmol), produced dose-dependent inhibition of DABK (100 nmol)-induced paw oedema in LPS-treated animals with mean IC50 of 134 nmol, while the selective B2 antagonists, Hoe 140 and NPC 17731 (each 10 nmol), had no effect. 5. Treatment of animals with dexamethasone (0.5 mg kg-1, s.c.) 24 or 48 h prior to LPS injection resulted in a graded inhibition of DABK (100 nmol)-induced oedema formation (58 +/- 3 and 82 +/- 2%, respectively), and almost reversed to control value oedema formation induced by T-BK (3 nmol) in LPS-pretreated rats. Cycloheximide (1 mg kg-1, s.c.) or indomethacin (2 mg kg-1, i.p.) pretreatment 24 and 1 h prior to LPS injection, respectively, markedly inhibited DABK (100 nmol)-induced paw oedema (98 +/- 2 and 50 +/- 4%, respectively). 6. Intraplantar injection of submaximal dose of DABK (10 nmol) in LPS-treated rats produced modest paw oedema (0.09 +/- 0.03 ml). However, i.pl. injections of PGE2, prostacyclin (PGI2), calcitonin-gene-related peptide (CGRP), SP, 5-HT, or platelet activating factor (PAF) (each 1 nmol), which alone caused little or no paw oedema, resulted in a potentiation of the DABK-induced oedema. The increases in paw volume (in ml) were: PGE2 + DABK (0.31 +/- 0.03), PGI2 + DABK (0.39 +/- 0.02), CGRP+DABK (0.35 +/- 0.04), DABK+SP (0.33 +/- 0.04), DABK + 5-HT (0.40 +/- 0.02) and DABK+PAF (0.38 +/- 0.016) ml. In contrast, histamine (1 nmol) was ineffective in potentiating the response to DABK. 7. The selective B1 receptor antagonist, DALBK (100-300 nmol), produced dose-dependent inhibition of paw oedema potentiation induced by co-injection of DABK and other mediators with mean ID50S (nmol) of: 180, 160, 139 and 135 in the presence of PGE2, PGI2, SP and 5-HT, respectively. 8. These results demonstrate that DABK-induced increase in paw volume in LPS-treated rats is probably mediated by induction of B1 receptors, associated with downregulation of B2 receptors. The induction of B1 receptors by LPS is sensitive to dexamethasone and cycloheximide treatment and requires activation of cyclo-oxygenase pathway. In addition, B1 receptors, when upregulated following LPS treatment, can interact in a synergistic manner with several inflammatory mediators such as PGI2, PGE2, CGRP, PAF and 5-HT. Such results indicate that induction of the B1 receptor might have a significant pathophysiological role in modulating chronic inflammatory diseases.

Expression of B1 kinin receptors mediating paw edema and formalin-induced nociception. Modulation by glucocorticoids

Bradykinin (BK) and Tyr8-BK induced graded rat paw edema with EC50 values of 1.9 and 1.1 nmol/paw, while des-Arg9-BK (DABK, up to 300 nmol/paw) was marginally effective. Tyr8-BK, but not DABK, also caused a dose-related increase in mouse paw edema, with an EC50 of 1.3 nmol/paw. The response to Tyr8-BK (10 nmol/paw) in rat paw edema was antagonized by B2 receptor antagonists (HOE-140 or NPC 17731, 30 nmol/paw) but not by the B1 antagonist des-Arg9[Leu8]BK (DALBK, 100 nmol/paw). Daily intraplantar injections of Tyr8-BK (10 nmol/paw) for 7 days caused progressive desensitization (D) of edema in sham-operated and adrenalectomized Wistar rats. DABK (100 nmol/paw) caused marked paw edema in D paws from both groups, which was inhibited by DALBK (100 nmol/paw) and by dexamethasone (0.5mg/kg, s.c.). Systemic injection of lipopolysaccharide (10 micrograms/mouse, 24 h prior) potentiated the first and second phases of Formalin-induced pain but had no effect on paw edema. Coinjection of DABK (2-22 nmol/paw) with low doses of Formalin in lipopolysaccharide-treated mice, which had no effect on naive animals, dose dependently potentiated both phases of Formalin-induced pain but did not modify paw edema. These effects were antagonized by DALBK with ID50 values of 21.9 (first phase) and 64.1 (second phase) nmol/paw. Thus, both progressive desensitization of B2 receptors and systemic treatment with lipopolysaccharide induce a glucocorticoid-sensitive upregulation of B1 receptors mediating paw edema in the rat and Formalin-induced nociception in mice. These results suggest that induction of upregulation of B1 receptors may play important roles in controlling inflammatory processes and hyperalgesia.

Deficit of T-cell recovery after allogeneic bone marrow transplantation in chronic myeloid leukemia patients

The immunological reconstitution that follows bone marrow transplantation (BMT) was studied in 40 leukaemia patients: 19 with chronic myeloid leukaemia (CML), 12 with acute myeloid leukaemia (AML) and the remaining 9 with acute lymphoblastic leukaemia (ALL). The recovery of the CML group was slower than that of the ALL and AML groups. This difference was produced by the T cell compartment, as NK cell activity and B cell numbers did not differ significantly. Factors such as conditioning treatment and graft versus host disease (GVHD) prophylaxis were analysed. Our experience suggests that all leukaemia patients should not be considered as one group when analysing their immunological reconstitution, as factors related to the original disease may affect their outcome.

Involvement of B1 and B2 receptors in bradykinin-induced rat paw oedema

1. The mechanisms involved in bradykinin (BK)-induced oedema in the rat paw as well as the interactions between BK and several inflammatory mediators, have been investigated. 2. Intraplantar injection of BK (1 nmol/paw) in rats pretreated with captopril (5 mg kg-1, s.c.) caused a small amount of oedema formation (0.17 +/- 0.05 ml). Des-Arg9-BK (DABK, a selective B1 receptor agonist) up to 300 nmol/paw caused minimal oedema (0.03 +/- 0.01 ml). 3. Co-administration of prostaglandin E2 (PGE2), prostaglandin I2 (PGI2), calcitonin gene-related peptide (CGRP), 5-hydroxytryptamine (5-HT), substance P (SP) or platelet activating factor (PAF) (1 pmol-1 nmol/paw) with BK (1 nmol/paw) dose-dependently potentiated BK-induced paw oedema. The rank order of potency (mean ED50, pmol/paw) for this effect was: SP (8.1) > PAF (13.7) > PGI2 (20.5) > 5-HT (23.8) > CGRP (25.7) > PGE2 (52.0). Co-administration of BK with the various inflammatory mediators resulted in maximal paw oedemas (ml) of: PGE2 (0.71 +/- 0.02); PGI2 (0.66 +/- 0.02); 5-HT (0.65 +/- 0.01); SP (0.63 +/- 0.05); CGRP (0.60 +/- 0.05) and PAF (0.47 +/- 0.02) ml. Histamine (up to 1 nmol/paw) was ineffective in potentiating the response to BK. 4. Hoe 140 or NPC 17731 (two selective B2 receptor antagonists, 0.1-3 nmol/paw) produced dose-dependent inhibition of paw oedema potentiation induced by co-injection of BK with other mediators with the following mean ID50s (nmol/paw): Hoe 140-1.4; 1.3; 1.5 and 1.1 and NPC 17731-1.0; 1.0; 0.9 and 0.7; in the presence of PGE2, PGI2, CGRP and SP, respectively. The selective B1 receptor antagonist des-Arg9 [Leu8]-BK (DALBK, up to 300 nmol/paw) had no effect.5. Daily intraplantar injections of BK (10 nmol/paw) once a day for 7 consecutive days caused a progressive and complete desensitization of the paw oedema, which was specific for BK, since paw oedema induced by PAF, PGE2, SP or histamine was not affected. In addition, the oedema caused by BK in the paw desensitized to the peptide was almost completely reversed if BK was co-injected with PGE2, PGI2 or SP (1 nmol/paw). Injection of PGE2 or SP (10 nmol/paw) together with the first BK injection (1O nmol/paw), partially prevented BK-induced desensitization.6. When animals were completely desensitized to BK, DABK (100nmol/paw) caused paw oedema(0.25 +/- 0.03 ml) which was consistently blocked by the B1 receptor antagonist, DALBK (100 nmol/paw).7. Treatment of animals with dexamethasone (0.5 mg kg-1, s.c., 24 h previously) antagonized paw oedema induced by DABK (100 nmol/paw) in desensitized paws, but not that induced by BK (3 nmol/paw) in naive paws. The steroid also prevented the recovery of oedema seen after co-injection of BK with PGE2 or PGI2 (1 nmol/paw) in desensitized paws.8. These results suggest that both B, and B2 receptors are involved in BK-induced rat paw oedema. The B2 receptors are constitutive, but induction of expression of B, receptors seems to occur only after complete desensitization of the paw to BK. In addition, very low doses of inflammatory mediators markedly potentiate BK-induced paw oedema and can attenuate BK-induced paw oedema desensitization.Such mechanisms may be relevant for the manifestation of acute and chronic inflammatory processes.

Inhibition of human LAK-cell activity by the anti-depressant trifluoperazine

The anti-depressive drug trifluoperazine (TFP) was studied on in vitro immune responses. TFP proved to be an inhibitor of lymphokine-activated killer (LAK) cells in its generative step, as well as in its effector phase. Natural killer (NK) activity and interleukin-2 (IL-2) or mitogen-induced lymphocyte proliferation were just as sensitive to the drug effects, whereas the division of tumor cells was more resistant. The mechanism through which TFP suppresses these lymphocytic systems remains unclear. It does not, however, affect an early stage of cellular activation as the addition of the drug as late as 24 h after the start of the culture was still inhibitory for lymphocyte mitogenesis. Neither the expression of CD25, nor that of CD56 was affected by TFP, and exogenous IL-2 was unable to overcome the suppression of proliferation. In relation to cell-mediated cytotoxicity, TFP partially interfered with the effector/target binding. However, addition of lectin to the assay did not overcome the inhibition of lysis produced by the drug. Although further work remains to be done, the effect of TFP on immune responses must be taken into consideration when treating immunosuppressed patients.