RESUMO
OBJECTIVE: We aimed to broaden our understanding of a potential interaction between B1R and TLR4, considering earlier studies suggesting that lipopolysaccharide (LPS) may trigger B1R stimulation. METHODS: We assessed the impact of DBK and LPS on the membrane potential of thoracic aortas from C57BL/6, B1R, or TLR4 knockout mice. Additionally, we examined the staining patterns of these receptors in the thoracic aortas of C57BL/6 and in endothelial cells (HBMEC). RESULTS: DBK does not affect the resting membrane potential of aortic rings in C57BL/6 mice, but it hyperpolarizes preparations in B1KO and TLR4KO mice. The hyperpolarization mechanism in B1KO mice involves B2R, and the TLR4KO response is independent of cytoplasmic calcium influx but relies on potassium channels. Conversely, LPS hyperpolarizes thoracic aorta rings in both C57BL/6 and B1KO mice, with the response unaffected by a B1R antagonist. Interestingly, the absence of B1R alters the LPS response to potassium channels. These activities are independent of nitric oxide synthase (NOS). While exposure to DBK and LPS does not alter B1R and TLR4 mRNA expression, treatment with these agonists increases B1R staining in endothelial cells of thoracic aortic rings and modifies the staining pattern of B1R and TLR4 in endothelial cells. Proximity ligation assay suggests a interaction between the receptors. CONCLUSION: Our findings provide additional support for a putative connection between B1R and TLR4 signaling. Given the involvement of these receptors and their agonists in inflammation, it suggests that drugs and therapies targeting their effects could be promising therapeutic avenues worth exploring.
Assuntos
Aorta Torácica , Células Endoteliais , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor B1 da Bradicinina , Receptor 4 Toll-Like , Animais , Masculino , Camundongos , Aorta Torácica/metabolismo , Bradicinina/farmacologia , Bradicinina/metabolismo , Células Cultivadas , Células Endoteliais/metabolismo , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Receptor B1 da Bradicinina/metabolismo , Receptor B1 da Bradicinina/genética , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , FemininoRESUMO
Although TRPV1 receptors play an essential role in the adverse effects on the airways following captopril treatment, there is no available evidence of their involvement in treatment regimens involving repeated doses of captopril. Comparing the difference in these two treatment regimens is essential since captopril is a continuous-use medication. Thus, this study explored the role of the transient receptor potential vanilloid 1 (TRPV1) in the effects of captopril on rat airways using two treatment regimens. Airway resistance, bronchoalveolar lavage (BAL), and histological and immunohistochemical analyses were conducted in rats administered with single or repeated doses of captopril. This study showed that the hyperresponsiveness to bradykinin and capsaicin in captopril-treated rats was acute. Treatment with the selective B2 antagonist, HOE140 reduced bradykinin hyperresponsiveness and abolished capsaicin exacerbation in single-dose captopril-treated rats. Likewise, degeneration of TRPV1-positive neurones also reduced hyperresponsiveness to bradykinin. Single-dose captopril treatment increased leukocyte infiltration in the BAL when compared with the vehicle and this increase was reduced by TRPV1-positive neurone degeneration. However, when compared with the vehicle treatment, animals treated with repeated doses of captopril showed an increase in leukocyte influx as early as 1 h after the last captopril treatment, but this effect disappeared after 24 h. Additionally, an increase in TRPV1 expression occurred only in animals who received repeated captopril doses and the degeneration of TRPV1-positive neurones attenuated TRPV1 upregulation. In conclusion, these data strongly indicate that a treatment regimen involving multiple doses of captopril not only enhances sensitisation but also upregulates TRPV1 expression. Consequently, targeting TRPV1 could serve as a promising strategy to reduce the negative impact of captopril on the airways.
Assuntos
Bradicinina , Líquido da Lavagem Broncoalveolar , Capsaicina , Captopril , Canais de Cátion TRPV , Animais , Captopril/farmacologia , Canais de Cátion TRPV/metabolismo , Ratos , Masculino , Bradicinina/farmacologia , Capsaicina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Ratos Sprague-Dawley , Resistência das Vias Respiratórias/efeitos dos fármacos , Antagonistas de Receptor B2 da Bradicinina/farmacologia , Relação Dose-Resposta a Droga , Hiper-Reatividade Brônquica/induzido quimicamente , Hiper-Reatividade Brônquica/tratamento farmacológico , Neurônios/efeitos dos fármacos , Neurônios/metabolismoRESUMO
Snake venoms contain various bradykinin-potentiating peptides (BPPs). First studied for their vasorelaxant properties due to angiotensin converting enzyme (ACE) inhibition, these molecules present a range of binding partners, among them the argininosuccinate synthase (AsS) enzyme. This has renewed interest in their characterization from biological sources and the evaluation of their pharmacological activities. In the present work, the low molecular weight fraction of Bothrops moojeni venom was obtained and BPPs were characterized by mass spectrometry. Eleven BPPs or related peptides were sequenced, and one of them, BPP-Bm01, was new. Interestingly, some oxidized BPPs were detected. The three most abundant peptides were BPP-Bm01, BPP-Bax12, and BPP-13a, and their putative interactions with the AsS enzyme were investigated in silico. A binding cavity for these molecules was predicted, and docking studies allowed their ranking. Three peptides were synthesized and submitted to vasorelaxation assays using rat aortic rings. While all BPPs were active, BPP-Bm01 showed the highest potency in this assay. This work adds further diversity to BPPs from snake venoms and suggests, for the first time, a putative binding pocket for these molecules in the AsS enzyme. This can guide the design of new and more potent AsS activators.
Assuntos
Aorta , Bothrops , Oligopeptídeos , Peptídeos , Serpentes Peçonhentas , Animais , Ratos , Brasil , Aorta/efeitos dos fármacos , Peptídeos/farmacologia , Peptídeos/química , Bradicinina/farmacologia , Masculino , Venenos de Crotalídeos/farmacologia , Venenos de Crotalídeos/química , Ratos Wistar , Venenos de Serpentes/farmacologia , Vasodilatadores/farmacologia , Vasodilatadores/química , Estrutura MolecularRESUMO
The kallikrein-kinin system is a versatile regulatory network implicated in various biological processes encompassing inflammation, nociception, blood pressure control, and central nervous system functions. Its physiological impact is mediated through G-protein-coupled transmembrane receptors, specifically the B1 and B2 receptors. Dopamine, a key catecholamine neurotransmitter widely distributed in the CNS, plays a crucial role in diverse physiological functions including motricity, reward, anxiety, fear, feeding, sleep, and arousal. Notably, the potential physical interaction between bradykinin and dopaminergic receptors has been previously documented. In this study, we aimed to explore whether B2R modulation in catecholaminergic neurons influences the dopaminergic pathway, impacting behavioral, metabolic, and motor aspects in both male and female mice. B2R ablation in tyrosine hydroxylase cells reduced the body weight and lean mass without affecting body adiposity, substrate oxidation, locomotor activity, glucose tolerance, or insulin sensitivity in mice. Moreover, a B2R deficiency in TH cells did not alter anxiety levels, exercise performance, or motor coordination in female and male mice. The concentrations of monoamines and their metabolites in the substantia nigra and cortex region were not affected in knockout mice. In essence, B2R deletion in TH cells selectively influenced the body weight and composition, leaving the behavioral and motor aspects largely unaffected.
Assuntos
Receptor B2 da Bradicinina , Tirosina 3-Mono-Oxigenase , Camundongos , Masculino , Feminino , Animais , Receptor B2 da Bradicinina/genética , Receptor B2 da Bradicinina/metabolismo , Tirosina 3-Mono-Oxigenase/genética , Bradicinina/farmacologia , Receptor B1 da Bradicinina/metabolismo , Peso Corporal , Camundongos KnockoutRESUMO
Anastrozole, an aromatase inhibitor, induces painful musculoskeletal symptoms, which affect patients' quality of life and lead to therapy discontinuation. Efforts have been made to understand the mechanisms involved in these painful symptoms to manage them better. In this context, we explored the role of the Transient Receptor Potential Vanilloid 4 (TRPV4), a potential transducer of several nociceptive mechanisms, in anastrozole-induced musculoskeletal pain in mice. Besides, we evaluated the possible sensibilization of TRPV4 by signalling pathways downstream, PLC, PKC and PKCε from kinin B2 (B2R) and B1 (B1R) receptors activation in anastrozole-induced pain. Anastrozole caused mechanical allodynia and muscle strength loss in mice. HC067047, TRPV4 antagonist, reduced the anastrozole-induced mechanical allodynia and muscle strength loss. In animals previously treated with anastrozole, the local administration of sub-nociceptive doses of the TRPV4 (4α-PDD or hypotonic solution), B2R (Bradykinin) or B1R (DABk) agonists enhanced the anastrozole-induced pain behaviours. The sensitizing effects induced by local injection of the TRPV4, B2R and B1R agonists in animals previously treated with anastrozole were reduced by pre-treatment with TRPV4 antagonist. Furthermore, inhibition of PLC, PKC or PKCε attenuated the mechanical allodynia and muscle strength loss induced by TRPV4, B2R and B1R agonists. The generation of painful conditions caused by anastrozole depends on direct TRPV4 activation or indirect, e.g., PLC, PKC and PKCε pathways downstream from B2R and B1R activation. Thus, the TRPV4 channels act as sensors of extracellular and intracellular changes, making them potential therapeutic targets for alleviating pain related to aromatase inhibitors use, such as anastrozole.
Assuntos
Antineoplásicos , Canais de Cátion TRPV , Humanos , Camundongos , Animais , Anastrozol , Hiperalgesia/induzido quimicamente , Qualidade de Vida , Receptor B1 da Bradicinina/metabolismo , Receptor B2 da Bradicinina/metabolismo , Dor/tratamento farmacológico , Bradicinina/farmacologiaRESUMO
Arterial hypertension is the main preventable cause of premature mortality worldwide. Across Latin America, hypertension has an estimated prevalence of 25.5-52.5%, although many hypertensive patients remain untreated. Appropriate treatment, started early and continued for the remaining lifespan, significantly reduces the risk of complications and mortality. All international and most regional guidelines emphasize a central role for renin-angiotensin-aldosterone system inhibitors (RAASis) in antihypertensive treatment. The two main RAASi options are angiotensin-converting enzyme inhibitors (ACEis) and angiotensin II receptor blockers (ARBs). Although equivalent in terms of blood pressure reduction, ACEis are preferably recommended by some guidelines to manage other cardiovascular comorbidities, with ARBs considered as an alternative when ACEis are not tolerated. This review summarizes the differences between ACEis and ARBs and their place in the international guidelines. It provides a critical appraisal of the guidelines based on available evidence from randomized controlled trials (RCTs) and meta-analyses, especially considering that hypertensive patients in daily practice often have other comorbidities. The observed differences in cardiovascular and renal outcomes in RCTs may be attributed to the different mechanisms of action of ACEis and ARBs, including increased bradykinin levels, potentiated bradykinin response, and stimulated nitric oxide production with ACEis. It may therefore be appropriate to consider ACEis and ARBs as different antihypertensive drugs classes within the same RAASi group. Although guideline recommendations only differentiate between ACEis and ARBs in patients with cardiovascular comorbidities, clinical evidence suggests that ACEis provide benefits in many hypertensive patients, as well as those with other cardiovascular conditions.
Assuntos
Inibidores da Enzima Conversora de Angiotensina , Hipertensão , Humanos , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Antagonistas de Receptores de Angiotensina/farmacologia , Antagonistas de Receptores de Angiotensina/uso terapêutico , Bradicinina/farmacologia , Bradicinina/uso terapêutico , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Sistema Renina-AngiotensinaRESUMO
Bradykinin (BK) is a peptide hormone that plays a crucial role in blood pressure control, regulates inflammation in the human body, and has recently been implicated in the pathophysiology of COVID-19. In this study, we report a strategy for fabricating highly ordered 1D nanostructures of BK using DNA fragments as a template for self-assembly. We have combined synchrotron small-angle X-ray scattering and high-resolution microscopy to provide insights into the nanoscale structure of BK-DNA complexes, unveiling the formation of ordered nanofibrils. Fluorescence assays hint that BK is more efficient at displacing minor-groove binders in comparison with base-intercalant dyes, thus, suggesting that interaction with DNA strands is mediated by electrostatic attraction between cationic groups at BK and the high negative electron density of minor-grooves. Our data also revealed an intriguing finding that BK-DNA complexes can induce a limited uptake of nucleotides by HEK-293t cells, which is a feature that has not been previously reported for BK. Moreover, we observed that the complexes retained the native bioactivity of BK, including the ability to modulate Ca2+ response into endothelial HUVEC cells. Overall, the findings presented here demonstrate a promising strategy for the fabrication of fibrillar structures of BK using DNA as a template, which keep bioactivity features of the native peptide and may have implications in the development of nanotherapeutics for hypertension and related disorders.
Assuntos
Bradicinina , COVID-19 , Humanos , Bradicinina/química , Bradicinina/farmacologia , Peptídeos , Transdução de Sinais , Células EndoteliaisRESUMO
Pain caused by the tumor or aromatase inhibitors (AIs) is a disabling symptom in breast cancer survivors. Their mechanisms are unclear, but pro-algesic and inflammatory mediators seem to be involved. Kinins are endogenous algogenic mediators associated with various painful conditions via B1 and B2 receptor activation, including chemotherapy-induced pain and breast cancer proliferation. We investigate the involvement of the kinin B1 and B2 receptors in metastatic breast tumor (4T1 breast cancer cells)-caused pain and in aromatase inhibitors (anastrozole or letrozole) therapy-associated pain. A protocol associating the tumor and antineoplastic therapy was also performed. Kinin receptors' role was investigated via pharmacological antagonism, receptors protein expression, and kinin levels. Mechanical and cold allodynia and muscle strength were evaluated. AIs and breast tumor increased kinin receptors expression, and tumor also increased kinin levels. AIs caused mechanical allodynia and reduced the muscle strength of mice. Kinin B1 (DALBk) and B2 (Icatibant) receptor antagonists attenuated these effects and reduced breast tumor-induced mechanical and cold allodynia. AIs or paclitaxel enhanced breast tumor-induced mechanical hypersensitivity, while DALBk and Icatibant prevented this increase. Antagonists did not interfere with paclitaxel's cytotoxic action in vitro. Thus, kinin B1 or B2 receptors can be a potential target for treating the pain caused by metastatic breast tumor and their antineoplastic therapy.
Assuntos
Antineoplásicos , Dor do Câncer , Neoplasias , Camundongos , Animais , Inibidores da Aromatase/farmacologia , Inibidores da Aromatase/uso terapêutico , Hiperalgesia/tratamento farmacológico , Hiperalgesia/metabolismo , Receptor B2 da Bradicinina/metabolismo , Receptor B1 da Bradicinina/metabolismo , Bradicinina/farmacologia , Dor , PaclitaxelRESUMO
Spatial confinement and temporal regulation of signaling by nitric oxide (NO) and reactive oxygen species (ROS) occurs in cancer cells. Signaling mediated by NO and ROS was investigated in two sub clones of the murine melanoma B16F10-Nex2 cell line, Nex10C and Nex8H treated or not with bradykinin (BK). The sub clone Nex10C, similar to primary site cells, has a low capacity for colonizing the lungs, whereas the sub clone Nex8H, similar to metastatic cells, corresponds to a highly invasive melanoma. BK-treated Nex10C cells exhibited a transient increase in NO and an inhibition in basal O2- levels. Inhibition of endogenous NO production by l-NAME resulted in detectable levels of O2-. l-NAME promoted Rac1 activation and enhanced Rac1-PI3K association. l-NAME in the absence of BK resulted in Nex10C cell migration and invasion, suggesting that NO is a negative regulator of O2- mediated cell migration and cell invasion. BK-treated Nex8H cells sustained endogenous NO production through the activation of NOS3. NO activated Rac1 and promoted Rac1-PI3K association. NO stimulated cell migration and cell invasion through a signaling axis involving Ras, Rac1 and PI3K. In conclusion, a role for O2- and NO as positive regulators of Rac1-PI3K signaling associated with cell migration and cell invasion is proposed respectively for Nex10C and Nex8H murine melanoma cells.
Assuntos
Bradicinina , Melanoma , Camundongos , Animais , Bradicinina/farmacologia , Bradicinina/metabolismo , Superóxidos , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/metabolismo , NG-Nitroarginina Metil Éster/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Movimento CelularRESUMO
The kinin receptors are classically involved in inflammation, pain and sepsis. The effects of the kinin B1 receptor agonist des-Arg9-bradykinin (DBK) and lipopolysaccharide (LPS) were investigated by comparing the membrane potential responses of aortic rings from transgenic rats overexpressing the kinin B1 receptor (B1R) in the endothelium (TGR(Tie2B1)) and Sprague Dawley (SD) rats. No difference in the resting membrane potential in the aorta's smooth muscle from the transgenic and SD rats was observed. The aorta rings from SD rats hyperpolarized only to LPS but not to DBK, whereas the aorta rings from TGR(Tie2B1) responded by the administration of both drugs. DBK and LPS responses were inhibited by the B1 receptor antagonist R715 and by iberiotoxin in both cases. Thapsigargin induced a hyperpolarization in the smooth muscle of SD rats that was not reversed by R715, but was reversed by iberiotoxin and this hyperpolarization was further augmented by DBK administration. These results show that the model of overexpression of vascular B1 receptors in the TGR(Tie2B1) rats represent a good model to study the role of functional B1 receptors in the absence of any pathological stimulus. The data also show that KCa channels are the final mediators of the hyperpolarizing responses to DBK and LPS. In addition, we suggest an interaction between the B1R and TLR4, since the hyperpolarization induced by LPS could be abolished in the presence of R715.
Assuntos
Bradicinina , Receptor B1 da Bradicinina , Animais , Aorta , Bradicinina/farmacologia , Endotélio Vascular , Técnicas In Vitro , Lipopolissacarídeos/farmacologia , Potenciais da Membrana , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos , Receptor B1 da Bradicinina/genética , Tapsigargina/farmacologia , Receptor 4 Toll-LikeRESUMO
BACKGROUND: Bradykinin (BK) is an endogenous peptide involved in vascular permeability and inflammation. It has opposite effects (inducing hyperalgesia or antinociception) when administered directly in the central nervous system. The aim of this study was to evaluate whether BK may also present this dual effect when injected peripherally in a PGE2-induced nociceptive pain model, as well as to investigate the possible mechanisms of action involved in this event in mice. METHODS: Male Swiss and C57BL/6 knockout mice for B1 or B2 bradykinin receptors were submitted to a mechanical paw pressure test and hyperalgesia was induced by intraplantar prostaglandin E2 (2 µg/paw) injection. RESULTS: Bradykinin (20, 40 and 80 ng/paw) produced dose-dependent peripheral antinociception against PGE2-induced hyperalgesia. This effect was antagonized by bradyzide (8, 16 and 32 µg/paw), naloxone (12.5, 25 and 50 µg/paw), nor-binaltorphimine (50, 100 and 200 µg/paw) and AM251 (20, 40 and 80 µg/paw). Bestatin (400 µg/paw), MAFP (0.5 µg/paw) and VDM11 (2.5 µg/paw) potentiated the antinociception of a lower 20 ng BK dose. The knockout of B1 or B2 bradykinin receptors partially abolished the antinociceptive action of BK (80 ng/paw), bremazocine (1 µg/paw) and anandamide (40 ng/paw) when compared with wild-type animals, which show complete antinociception with the same dose of each drug. CONCLUSION: The present study is the first to demonstrate BK-induced antinociception in peripheral tissues against PGE2-induced nociception in mice and the involvement of κ-opioid and CB1 cannabinoid receptors in this effect.
Assuntos
Bradicinina , Hiperalgesia , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Animais , Bradicinina/farmacologia , Dinoprostona , Hiperalgesia/induzido quimicamente , Hiperalgesia/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores da BradicininaRESUMO
BACKGROUND AND PURPOSE: Bradykinin (BK-(1-9)) is an endogenous nonapeptide involved in multiple physiological and pathological processes. Peptide fragments of bradykinin are believed to be biologically inactive. We have now tested the two major peptide fragments of bradykinin in human and animals. EXPERIMENTAL APPROACH: BK peptides were quantified by MS in male rats. NO release was quantified from human, mouse and rat cells loaded with DAF-FM. Rat aortic rings were used to measure vascular reactivity. Changes in BP and HR were measured in conscious male rats. To evaluate pro-inflammatory effects both vascular permeability and nociception were measured in adult mice. KEY RESULTS: BK-(1-7) and BK-(1-5) are produced in vivo from BK-(1-9). Both peptides induced NO production in all cell types tested. However, unlike BK-(1-9), NO production elicited by BK-(1-7) or BK-(1-5) was not inhibited by B1 or B2 receptor antagonists. BK-(1-7) and BK-(1-5) induced concentration-dependent vasorelaxation of aortic rings, without involvement of B1 or B2 receptors. Intravenous or intra-arterial administration of BK-(1-7) or BK-(1-5) induced similar hypotensive response in vivo. Nociceptive responses of BK-(1-7) and BK-(1-5) were reduced compared to BK-(1-9), and no increase in vascular permeability was observed for BK-(1-9) fragments. CONCLUSIONS AND IMPLICATIONS: BK-(1-7) and BK-(1-5) are endogenous peptides present in plasma. BK-related peptide fragments show biological activity, not mediated by B1 or B2 receptors. These BK fragments could constitute new, active components of the kallikrein-kinin system.
Assuntos
Bradicinina , Receptores da Bradicinina , Animais , Bradicinina/farmacologia , Masculino , Camundongos , Fragmentos de Peptídeos , Ratos , Receptor B1 da Bradicinina , Receptor B2 da Bradicinina , Receptores da Bradicinina/fisiologiaRESUMO
Dry cough has been reported in patients receiving statin therapy. However, the underlying mechanism or other possible alterations in the airways induced by statins remain unknown. Thus, the aim of this study was to evaluate whether simvastatin promotes alterations in airways, such as bronchoconstriction and plasma extravasation, as well as the mechanism involved in these events. Using methods to detect alterations in airway resistance and plasma extravasation, we demonstrated that simvastatin [20 mg/kg, intravenous (i.v.)] caused plasma extravasation in the trachea (79.8 + 14.8 µg/g/tissue) and bronchi (73.3 + 8.8 µg/g/tissue) of rats, compared to the vehicle (34.2 + 3.6 µg/g/tissue and 29.3 + 5.3 µg/g/tissue, respectively). NG-nitro-L-arginine methyl ester (L-NAME, 30 mg/kg, intraperitoneal), a nitric oxide (NO) synthase inhibitor, Icatibant [HOE 140, 10 nmol/50 µl, intratracheal (i.t.)], a bradykinin B2 antagonist, and capsazepine (100 nmol/50 µl, i.t.), a TRPV1 antagonist, attenuated simvastatin-induced plasma extravasation. Simvastatin (5, 10 and 20 mg/kg) did not cause bronchoconstriction per se, but exacerbated the bronchoconstrictive response to bradykinin (30 nmol/kg, i.v.), a B2 agonist (0.7 + 0.1 ml/H2O), or capsaicin (30 nmol/kg, i.v.), a TRPV1 agonist (0.8 + 0.1 ml/H2O), compared to the vehicle (0.1 + 0.04 ml/H2O and 0.04 + 0.01 ml/H2O, respectively). The bronchoconstriction elicited by bradykinin (100 nmol/kg, i.v.) in simvastatin non-treated rats was inhibited by L-NAME. The exacerbation of bronchoconstriction induced by bradykinin or capsaicin in simvastatin-treated rats was inhibited by L-NAME, HOE 140 or capsazepine. These results suggest that treatment with simvastatin promotes the release of bradykinin, which, via B2 receptors, releases NO that can then activate the TRPV1 to promote plasma extravasation and bronchoconstriction.
Assuntos
Brônquios/efeitos dos fármacos , Óxido Nítrico/metabolismo , Receptor B2 da Bradicinina/metabolismo , Sinvastatina/efeitos adversos , Canais de Cátion TRPV/metabolismo , Traqueia/efeitos dos fármacos , Administração Intravenosa , Resistência das Vias Respiratórias/efeitos dos fármacos , Animais , Bradicinina/administração & dosagem , Bradicinina/análogos & derivados , Bradicinina/farmacologia , Antagonistas de Receptor B2 da Bradicinina/administração & dosagem , Antagonistas de Receptor B2 da Bradicinina/farmacologia , Brônquios/metabolismo , Broncoconstrição/efeitos dos fármacos , Permeabilidade Capilar/efeitos dos fármacos , Capsaicina/administração & dosagem , Capsaicina/análogos & derivados , Capsaicina/farmacologia , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Injeções Intraperitoneais , Masculino , NG-Nitroarginina Metil Éster/administração & dosagem , NG-Nitroarginina Metil Éster/farmacologia , Ratos Wistar , Sinvastatina/administração & dosagem , Canais de Cátion TRPV/antagonistas & inibidores , Traqueia/metabolismoRESUMO
Megalin-mediated albumin endocytosis plays a critical role in albumin reabsorption in proximal tubule (PT) epithelial cells (PTECs). Some studies have pointed out the modulatory effect of bradykinin (BK) on urinary protein excretion, but its role in PT protein endocytosis has not yet been determined. Here, we studied the possible correlation between BK and albumin endocytosis in PT. Using LLC-PK1 cells, a model of PTECs, we showed that BK specifically inhibited megalin-mediated albumin endocytosis. This inhibitory effect of BK was mediated by B2 receptor (B2R) because it was abolished by HOE140, an antagonist of B2R, but it was not affected by Lys-des-Arg9-BK, an antagonist of B1. BK induced the stall of megalin in EEA1+ endosomes, but not in LAMP1+ lysosomes, leading to a decrease in surface megalin expression. In addition, we showed that BK, through B2R, activated calphostin C-sensitive protein kinase C, which mediated its effect on the surface megalin expression and albumin endocytosis. These results reveal an important modulatory mechanism of PT albumin endocytosis by BK, which opens new possibilities to understanding the effect of BK on urinary albumin excretion.
Assuntos
Albuminas/metabolismo , Bradicinina/farmacologia , Endocitose/efeitos dos fármacos , Túbulos Renais Proximais/efeitos dos fármacos , Proteína-2 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Animais , Linhagem Celular , Ativação Enzimática , Túbulos Renais Proximais/metabolismo , Células LLC-PK1 , Proteína Quinase C/metabolismo , Receptor B2 da Bradicinina/metabolismo , SuínosRESUMO
Although progesterone has the ability to promote dilation of vascular smooth muscle, its role in coronary circulation is still poorly characterized, especially in essential hypertension and in a model of endogenous deficiency of ovarian hormones. Thus, this study evaluated the effect of progesterone treatment on endothelium-dependent coronary vascular reactivity in hypertensive (SHR) and ovariectomized rats. Adult SHR aged 8-10 weeks were divided into: SHAM, Ovariectomized (OVX) and Ovariectomized + treatment with 2 mg/kg/day of progesterone for 15 days (OVX-P4). Coronary vascular reactivity was investigated using the modified Langendorff method. After stabilization, baseline coronary perfusion pressure (CPP) was recorded and vascular reactivity to bradykinin (BK, 0.1-1000 ng) were assessed before and after infusion, either individually or in combination, with Nω-nitro-l-arginine methyl ester (l-NAME), indomethacin or clotrimazole. Scanning electron microscopy was used for qualitative analysis of the endothelium. OVX and OVX-P4 groups had a higher baseline CPP compared to that of the SHAM group. BK was able to promote vasodilation in all groups. However, relaxation to BK was less pronounced in the OVX group when compared to SHAM, with architecture loss and areas of cell atrophy having been observed. Progesterone treatment prevented this injury. Perfusion with l-NAME induced greater damage to the SHAM group, while the use of indomethacin led to a significant reduction in the vasodilator response to BK in the OVX-P4 group. Taken together, our results show that progesterone modulates endothelium-dependent coronary vasodilation in SHR ovariectomized, preventing damage caused by ovarian hormonal deficiency through a mechanism that involves prostanoid pathway.
Assuntos
Vasos Coronários/patologia , Endotélio Vascular/patologia , Hipertensão/patologia , Progesterona/farmacologia , Animais , Pressão Sanguínea/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Bradicinina/farmacologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/ultraestrutura , Endotélio Vascular/efeitos dos fármacos , Feminino , Tamanho do Órgão/efeitos dos fármacos , Perfusão , Ratos Endogâmicos SHR , Sístole/efeitos dos fármacos , Útero/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologiaRESUMO
Physiological or supraphysiological levels of testosterone appear to be associated with the development of risk factors for cardiovascular diseases such as hypertension, as this hormone modulates the release of endothelial factors. However, its actions are still controversial, especially in the coronary circulation of hypertensive animals. This study was designed to assess the effects of testosterone treatment (T) on endothelium-dependent coronary vascular reactivity in orchiectomized SHR. The animals were divided into SHAM, orchiectomized (ORX), ORX+T and ORX+T+aromatase inhibitor (AI). All treatments lasted 15 days. Blood pressure (BP) was measured. Dose-response curves to bradykinin (BK) were constructed using the Langendorff technique, followed by inhibition of endothelium mediators (NO, prostanoids, EETs) and potassium channels. The intensity of eNOS, COX-1, COX-2, Akt, and gp91phox protein expression was quantified by Western blotting. BP was elevated in SHAM, ORX+T, and ORX+T+AI groups. However, we did not observe differences in the ORX group. Baseline coronary perfusion pressure (CPP) remained unaffected. Orchiectomy did not change the BK-induced relaxation compared to the SHAM group, whereas testosterone treatment increased it. This response was diminished in the absence of NO, prostanoids, and EETs in the SHAM and ORX groups, while in ORX+T group the relaxation was diminished only in the absence of NO and EETs. There was no difference in eNOS, COX-1, COX-2, and gp91phox protein expression, though Akt expression was increased in ORX and ORX+T groups. These results show that testosterone treatment can modulate endothelial function, especially in the coronary circulation under hypertension conditions, via NO and EETs pathways.
Assuntos
Bradicinina/farmacologia , Vasos Coronários/efeitos dos fármacos , Vasos Coronários/fisiopatologia , Testosterona/farmacologia , Vasodilatação/efeitos dos fármacos , Animais , Biomarcadores , Pressão Sanguínea , Modelos Animais de Doenças , Suscetibilidade a Doenças , Relação Dose-Resposta a Droga , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Hipertensão/etiologia , Hipertensão/metabolismo , Masculino , Ratos , Ratos Endogâmicos SHR , Transdução de Sinais/efeitos dos fármacosRESUMO
PURPOSE: To investigate the effects of bradykinin on reperfusion injury in an experimental intestinal ischemia reperfusion model. METHODS: We used 32 Wistar-Albino rats. We composed 4 groups each containing 8 rats. Rats in sham group were sacrified at 100 minutes observation after laparotomy. Thirty minutes reperfusion was performed following 50 minutes ischaemia in control group after observing 20 minutes. Ischaemic preconditioning was performed in one group of the study. We performed the other study group pharmacologic preconditioning by infusional administration of 10 µg/kg/minute bradykinin intravenously. We sacrified all of the rats by taking blood samples to evaluate the lactate and lactate dehydrogenase (LDH) after resection of jejunum for detecting tissue myeloperoxidase (MPO) activity. RESULTS: Lactate and LDH levels were significantly higher in control and study groups than the sham group (P<0.001). There is no difference between the study groups statistically. (P>0.05). The results were the same for MPO levels. Although definitive cell damage was determinated in the control group by hystopatological evaluation, the damage in the study groups observed was lower in different levels. However, there was no significant difference between the study groups statistically (P>0.05). CONCLUSION: Either ischeamic preconditioning or pharmacologic preconditioning made by bradykinin reduced the ischemia reperfusion injury at jejunum.
Assuntos
Bradicinina/farmacologia , Modelos Animais de Doenças , Intestino Delgado/irrigação sanguínea , Precondicionamento Isquêmico/métodos , Traumatismo por Reperfusão/prevenção & controle , Vasodilatadores/farmacologia , Animais , Feminino , Laparotomia , Peroxidase/análise , Distribuição Aleatória , Ratos Wistar , Valores de Referência , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do TratamentoRESUMO
Abstract Purpose To investigate the effects of bradykinin on reperfusion injury in an experimental intestinal ischemia reperfusion model. Methods We used 32 Wistar-Albino rats. We composed 4 groups each containing 8 rats. Rats in sham group were sacrified at 100 minutes observation after laparotomy. Thirty minutes reperfusion was performed following 50 minutes ischaemia in control group after observing 20 minutes. Ischaemic preconditioning was performed in one group of the study. We performed the other study group pharmacologic preconditioning by infusional administration of 10 μg/kg/minute bradykinin intravenously. We sacrified all of the rats by taking blood samples to evaluate the lactate and lactate dehydrogenase (LDH) after resection of jejunum for detecting tissue myeloperoxidase (MPO) activity. Results Lactate and LDH levels were significantly higher in control and study groups than the sham group (P<0.001). There is no difference between the study groups statistically. (P>0.05). The results were the same for MPO levels. Although definitive cell damage was determinated in the control group by hystopatological evaluation, the damage in the study groups observed was lower in different levels. However, there was no significant difference between the study groups statistically (P>0.05). Conclusion Either ischeamic preconditioning or pharmacologic preconditioning made by bradykinin reduced the ischemia reperfusion injury at jejunum.
Assuntos
Animais , Feminino , Vasodilatadores/farmacologia , Bradicinina/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Precondicionamento Isquêmico/métodos , Modelos Animais de Doenças , Intestino Delgado/efeitos dos fármacos , Valores de Referência , Fatores de Tempo , Distribuição Aleatória , Reprodutibilidade dos Testes , Resultado do Tratamento , Ratos Wistar , Peroxidase/análise , LaparotomiaRESUMO
BACKGROUND AND PURPOSE: Bradykinin may induce vasoconstriction in selected vessels or under specific experimental conditions. We hypothesized that inflammatory stimuli, such as endotoxin challenge, may induce the dimerization of AT1 /B2 receptors, altering the vascular effects of bradykinin. EXPERIMENTAL APPROACH: Wistar rats received LPS (1 mg·kg-1 , i.p.) and were anaesthetized for assessment of BP. Mesenteric resistance arteries were used in organ baths and subjected to co-immunoprecipitation and Western blot analyses. KEY RESULTS: At 24 and 48 hr after LPS, bradykinin-induced hypotension was followed by a sustained increase in BP, which was not found in non-endotoxemic animals. The B2 receptor antagonist Hoe-140 fully blocked the responses to bradykinin. The pressor effect of bradykinin was not prevented by prazosin, an α1 -adrenoceptor antagonist, but it was inhibited by the AT1 receptor antagonist losartan or the Rho-kinase inhibitor Y-27632. Endotoxemic rats also displayed enhanced pressor responses to angiotensin II, which were blocked by Hoe-140. Co-immunoprecipitation isolated using anti-B2 or anti-AT1 receptor antibodies showed that resistance arteries presented augmented levels of the AT1 /B2 receptor complexes at 24 hr after LPS injection. The presence of AT1 /B2 receptor heterodimers did correlate with the development of losartan-sensitive contractile responses to bradykinin and potentiation of angiotensin II-induced contraction, which was prevented by Hoe-140. CONCLUSIONS AND IMPLICATIONS: Endotoxin challenge is a stimulus for AT1 /B2 receptor heterodimerization in native vessels and shifts the B2 receptor-dependent vascular effect of bradykinin to a more complex pathway, which also depends on AT1 receptors and their intracellular signalling pathways.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Bradicinina/farmacologia , Receptor Tipo 1 de Angiotensina/metabolismo , Receptor B2 da Bradicinina/metabolismo , Vasodilatadores/farmacologia , Angiotensina II/administração & dosagem , Angiotensina II/farmacologia , Animais , Bradicinina/administração & dosagem , Dimerização , Feminino , Injeções Intraperitoneais , Injeções Intravenosas , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Masculino , Ratos , Ratos Wistar , Vasodilatadores/administração & dosagemRESUMO
Schistosomiasis mansoni is involved in hepatic fibrogenesis and portal hypertension. Previous studies proved that blockade of some components of the renin-angiotensin system (RAS) reduce liver fibrogenesis. However, the effects of inhibition of early stages of RAS pathway in schistosomal fibrosis have not been studied yet. Thus, the aim of this study was to compare the role of different antihypertensive drugs on hepatic fibrosis in murine schistosomiasis. BALB/c mice (nâ¯=â¯50) weighing 20g were subjected to inoculation of 50 cercariae and submitted to different treatments: aliskiren, 50â¯mg/kg (nâ¯=â¯10); bradykinin, 2⯵g/kg (nâ¯=â¯5); losartan, 10â¯mg/kg (nâ¯=â¯10); lisinopril 10â¯mg/kg (nâ¯=â¯5) and control, proportional volume vehicle (nâ¯=â¯5); daily for 14 weeks. Six animals were not subjected to cercariae inoculation or any type of treatment. Ultrasound, histological, immunohistochemical and proteomic analyzes were performed to evaluate markers associated with hepatic fibrogenesis. The hepatic areas stained with Sirius red and thenumber of cells marked by α-SMA in animals treated with aliskiren, bradykinin, lisinopril and losartan were diminished when compared to control group, demonstrating reduced hepatic fibrosis after RAS blockade. These results were reinforced by ultrasonography analysis and protein expression of TGFß. These findings demonstrated the effect of RAS inhibition on hepatic fibrosis in murine schistosomiasis, with the most evident results being observed in the losartan and aliskiren treated groups. The main mechanisms underlying this process appear to involve anti-fibrogenic activity through the inhibition of collagen and TGFß synthesis.