1
|
Liang D, He X, Wang Z, Li C, Gao B, Wu J, Bai Y. Remote limb ischemic postconditioning promotes motor function recovery in a rat model of ischemic stroke via the up-regulation of endogenous tissue kallikrein. CNS Neurosci Ther 2018; 24:519-527. [PMID: 29399973 PMCID: PMC6489769 DOI: 10.1111/cns.12813] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 12/27/2017] [Accepted: 12/29/2017] [Indexed: 01/16/2023] Open
Abstract
AIMS Remote ischemic conditionings, such as pre- and per-conditioning, are known to provide cardioprotection in animal models of ischemia. However, little is known about the neuroprotection effect of postconditioning after cerebral ischemia. In this study, we aim to evaluate the motor function rescuing effect of remote limb ischemic postconditioning (RIPostC) in a rat model of acute cerebral stroke. METHODS Left middle cerebral artery occlusion (MCAO) was performed to generate the rat model of ischemic stroke, followed by daily RIPostC treatment for maximum 21 days. The motor function after RIPostC was assessed with foot fault test and balance beam test. Local infarct volume was measured through MRI scanning. Neuronal status was evaluated with Nissl's, HE, and MAP2 immunostaining. Lectin immunostaining was performed to evaluate the microvessel density and area. RESULTS Daily RIPostC for more than 21 days promoted motor function recovery and provided long-lasting neuroprotection after MCAO. Reduced infarct volume, rescued neuronal loss, and enhanced microvessel density and size in the injured areas were observed. In addition, the RIPostC effect was associated with the up-regulation of endogenous tissue kallikrein (TK) level in circulating blood and local ischemic brain regions. A TK receptor antagonist HOE-140 partially reversed RIPostC-induced improvements, indicating the specificity of endogenous TK mediating the neuroprotection effect of RIPostC. CONCLUSION Our study demonstrates RIPostC treatment as an effective rehabilitation therapy to provide motor function recovery and alleviate brain impairment in a rat model of acute cerebral ischemia. We also for the first time provide evidence showing that the up-regulation of endogenous TK from remote conditioning regions underlies the observed effects of RIPostC.
Collapse
Affiliation(s)
- Dan Liang
- Department of Rehabilitation MedicineHuashan HospitalFudan UniversityShanghaiChina
| | - Xi‐Biao He
- Shanghai University of Medicine & Health SciencesShanghaiChina
| | - Zheng Wang
- Department of NeurologyHuashan HospitalState Key Laboratory of Medical NeurobiologyFudan UniversityShanghaiChina
| | - Ce Li
- Department of Rehabilitation MedicineHuashan HospitalFudan UniversityShanghaiChina
| | - Bei‐Yao Gao
- Department of Rehabilitation MedicineHuashan HospitalFudan UniversityShanghaiChina
| | - Jun‐Fa Wu
- Department of Rehabilitation MedicineHuashan HospitalFudan UniversityShanghaiChina
| | - Yu‐Long Bai
- Department of Rehabilitation MedicineHuashan HospitalFudan UniversityShanghaiChina
| |
Collapse
|
2
|
Sobczuk P, Szczylik C, Porta C, Czarnecka AM. Renin angiotensin system deregulation as renal cancer risk factor. Oncol Lett 2017; 14:5059-5068. [PMID: 29098020 PMCID: PMC5652144 DOI: 10.3892/ol.2017.6826] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 08/03/2017] [Indexed: 12/20/2022] Open
Abstract
For numerous years, the non-cardiovascular role of the renin-angiotensin system (RAS) was underestimated, but recent studies have advanced the understanding of its function in various processes, including carcinogenesis. Numerous evidence comes from preclinical and clinical studies on the use of antihypertensive agents targeting the RAS, including angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers. It has been demonstrated that the use of ACEIs can alter the incidence of renal cell carcinoma (RCC) and may have a positive effect by prolonging patient survival. It has an effect on the complex action of ACEI, resulting in decreased angiotensin II (Ang-II) production and altered levels of bradykinin or Ang 1-7. The present review discusses the existing knowledge on the effects of ACE and its inhibitors on RCC cell lines, xenograft models, and patient survival in clinical studies. A brief introduction to molecular pathways aids in understanding the non-cardiovascular effects of RAS inhibitors and enables the conduction of studies on combined cancer treatment with the application of ACEIs. Recent evidence regarding the treatment of hypertension associated with tyrosine kinase inhibitors, one of the most pronounced and common side effects in modern RCC treatment, are also outlined. Captopril, an ACEI, may be used to lower blood pressure in patients, particularly due to its additional renoprotective actions.
Collapse
Affiliation(s)
- Paweł Sobczuk
- Department of Oncology, Military Institute of Medicine, 04-141 Warsaw, Poland.,Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, 02-097 Warsaw, Poland
| | - Cezary Szczylik
- Department of Oncology, Military Institute of Medicine, 04-141 Warsaw, Poland
| | - Camillo Porta
- Medical Oncology, I.R.C.C.S. San Matteo University Hospital Foundation, I-27100 Pavia, Italy.,Italian Group of Onco-Nephrology/Gruppo Italiano di Onco-Nefrologia (G.I.O.N.), I-27100 Pavia, Italy
| | - Anna M Czarnecka
- Department of Oncology, Military Institute of Medicine, 04-141 Warsaw, Poland
| |
Collapse
|
3
|
Control of ENaC-mediated sodium reabsorption in the distal nephron by Bradykinin. VITAMINS AND HORMONES 2015. [PMID: 25817868 DOI: 10.1016/bs.vh.2014.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
Kinins, such as Bradykinin (BK), are peptide hormones of the kallikrein-kinin system. Apart from being a vasodilator, BK also increases urinary sodium excretion to reduce systemic blood pressure. It is becoming appreciated that BK modulates function of the epithelial Na(+) channel in the distal part of the renal nephron to affect tubular sodium reabsorption. In this chapter, we outline the molecular details, as well as discuss the physiological relevance of this regulation for the whole organism sodium homeostasis and setting chronic blood pressure.
Collapse
|
4
|
Direct regulation of ENaC by bradykinin in the distal nephron. Implications for renal sodium handling. Curr Opin Nephrol Hypertens 2014; 23:122-9. [PMID: 24378775 DOI: 10.1097/01.mnh.0000441053.81339.61] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Locally produced peptide hormones kinins, such as bradykinin, are thought to oppose many of the prohypertensive actions of the renin-angiotensin-aldosterone system. In the kidney, bradykinin, via stimulation of B2 receptors (B2R), favors natriuresis mostly due to the inhibition of tubular Na reabsorption. Recent experimental evidence identifies the epithelial Na channel (ENaC) as a key end effector of bradykinin actions in the distal tubular segments. The focus of this review is the physiological relevance and molecular details of the bradykinin signal to ENaC. RECENT FINDINGS The recent epidemiological GenSalt study demonstrated that genetic variants of the gene encoding B2R show significant associations with the salt sensitivity of blood pressure. Bradykinin was shown to have an inhibitory effect on the distal nephron sodium transport via stimulation of B2 receptor-phospholipase C (B2R-PLC) cascade to decrease ENaC open probability. Genetic ablation of bradykinin receptors in mice led to an augmented ENaC function, particularly during elevated sodium intake, likely contributing to the salt-sensitive hypertensive phenotype. Furthermore, augmentation of bradykinin signaling in the distal nephron was demonstrated to be an important component of the natriuretic and antihypertensive effects of angiotensin converting enzyme inhibition. SUMMARY Salt-sensitive inhibition of ENaC activity by bradykinin greatly advances our understanding of the molecular mechanisms that are responsible for shutting down distal tubule sodium reabsorption during volume expanded conditions to avoid salt-sensitive hypertension.
Collapse
|
5
|
Kramarenko II, Morinelli TA, Bunni MA, Raymond JR, Garnovskaya MN. The bradykinin B(2) receptor induces multiple cellular responses leading to the proliferation of human renal carcinoma cell lines. Cancer Manag Res 2012; 4:195-205. [PMID: 22904641 PMCID: PMC3421467 DOI: 10.2147/cmar.s31847] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background The vasoactive peptide bradykinin (BK) acts as a potent growth factor for normal kidney cells, but there have been few studies on the role of BK in renal cell carcinomas. Purpose In this study, we tested the hypothesis that BK also acts as a mitogen in kidney carcinomas, and explored the effects of BK in human renal carcinoma A498 cells. Methods The presence of mRNAs for BK B1 and BK B2 receptors in A498 cells was demonstrated by reverse transcription–polymerase chain reaction. To study BK signaling pathways, we employed fluorescent measurements of intracellular Ca2+, measured changes in extracellular pH as a reflection of Na+/H+ exchange (NHE) with a Cytosensor microphysiometer, and assessed extracellular signal-regulated kinase (ERK) activation by Western blotting. Results Exposure to 100 nM of BK resulted in the rapid elevation of intracellular Ca2+, caused a ≥30% increase in NHE activity, and a ≥300% increase in ERK phosphorylation. All BK signals were blocked by HOE140, a BK B2 receptor antagonist, but not by a B1 receptor antagonist. Inhibitor studies suggest that BK-induced ERK activation requires phospholipase C and protein kinase C activities, and is Ca2+/calmodulin-dependent. The amiloride analog 5-(N-methyl-N-isobutyl)-amiloride (MIA) blocked short-term NHE activation and inhibited ERK phosphorylation, suggesting that NHE is critical for ERK activation by BK. BK induced an approximately 40% increase in the proliferation of A498 cells as assessed by bromodeoxyuridine uptake. This effect was blocked by the ERK inhibitor PD98059, and was dependent on NHE activity. Conclusion We conclude that BK exerts mitogenic effects in A498 cells via the BK B2 receptor activation of growth-associated NHE and ERK.
Collapse
Affiliation(s)
- Inga I Kramarenko
- Department of Medicine (Nephrology Division), Medical University of South Carolina, Charleston, SC, USA
| | | | | | | | | |
Collapse
|
6
|
Sorensen CM, Braunstein TH, Holstein-Rathlou NH, Salomonsson M. Role of vascular potassium channels in the regulation of renal hemodynamics. Am J Physiol Renal Physiol 2012; 302:F505-18. [DOI: 10.1152/ajprenal.00052.2011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
K+ conductance is a major determinant of membrane potential ( Vm) in vascular smooth muscle (VSMC) and endothelial cells (EC). The vascular tone is controlled by Vm through the action of voltage-operated Ca2+ channels (VOCC) in VSMC. Increased K+ conductance leads to hyperpolarization and vasodilation, while inactivation of K+ channels causes depolarization and vasoconstriction. K+ channels in EC indirectly participate in the control of vascular tone by several mechanisms, e.g., release of nitric oxide and endothelium-derived hyperpolarizing factor. In the kidney, a change in the activity of one or more classes of K+ channels will lead to a change in hemodynamic resistance and therefore of renal blood flow and glomerular filtration pressure. Through these effects, the activity of renal vascular K+ channels influences renal salt and water excretion, fluid homeostasis, and ultimately blood pressure. Four main classes of K+ channels [calcium activated (KCa), inward rectifier (Kir), voltage activated (KV), and ATP sensitive (KATP)] are found in the renal vasculature. Several in vitro experiments have suggested a role for individual classes of K+ channels in the regulation of renal vascular function. Results from in vivo experiments are sparse. We discuss the role of the different classes of renal vascular K+ channels and their possible role in the integrated function of the renal microvasculature. Since several pathological conditions, among them hypertension, are associated with alterations in K+ channel function, the role of renal vascular K+ channels in the control of salt and water excretion deserves attention.
Collapse
Affiliation(s)
- Charlotte Mehlin Sorensen
- Institute of Biomedical Sciences, Division of Renal and Vascuar Physiology, The Panum Institute, and
| | - Thomas Hartig Braunstein
- Danish National Research Foundation Center for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark
| | | | - Max Salomonsson
- Institute of Biomedical Sciences, Division of Renal and Vascuar Physiology, The Panum Institute, and
| |
Collapse
|
7
|
Kramarenko II, Bunni MA, Morinelli TA, Raymond JR, Garnovskaya MN. Identification of functional bradykinin B(2) receptors endogenously expressed in HEK293 cells. Biochem Pharmacol 2008; 77:269-76. [PMID: 18938142 DOI: 10.1016/j.bcp.2008.09.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 09/19/2008] [Accepted: 09/22/2008] [Indexed: 11/29/2022]
Abstract
The human embryonic kidney (HEK) 293 cell line is widely used in cell biology research. Although HEK293 cells have been meticulously studied, our knowledge about endogenous G protein-coupled receptors (GPCR) in these cells is incomplete. While studying the effects of bradykinin (BK), a potent growth factor for renal cells, we unexpectedly discovered that BK activates extracellular signal-regulated protein kinase 1 and 2 (ERK) in HEK293 cells. Thus, we hypothesized that HEK293 cells possess endogenous BK receptors. RT-PCR demonstrated the presence of mRNAs for BK B(1) and BK B(2) receptors in HEK293 cells. Western blotting with BK B(1) and BK B(2) receptor antibodies confirmed this result at the protein level. To establish that BK receptors are functional, we employed fluorescent measurements of intracellular Ca(2+), measured changes in extracellular acidification rate (ECAR) as a reflection of the Na(+)/H(+) exchange (NHE) with a Cytosensortrade microphysiometer, and assessed ERK activation by Western blotting with a phospho-specific ERK antibody. Exposure of HEK293 cells to BK produced a concentration-dependent rise in intracellular Ca(2+) (EC(50)=36.5+/-8.0 x 10(-9)M), a rapid increase in tyrosine phosphorylation of ERK (EC(50)=9.8+/-0.4 x 10(-9)M), and elevation in ECAR by approximately 20%. All of these signals were blocked by HOE-140 (B(2) receptor antagonist) but not by des-Arg(10)-HOE-140 (B(1) receptor antagonist). We conclude that HEK293 cells express endogenous functional BK B(2) receptors, which couple to the mobilization of intracellular Ca(2+), increases in ECAR and increases in ERK phosphorylation.
Collapse
Affiliation(s)
- Inga I Kramarenko
- Medical and Research Services of the Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC 29401, USA
| | | | | | | | | |
Collapse
|
8
|
Uhlmann D, Lauer H, Serr F, Witzigmann H. Pathophysiological role of platelets and platelet system in acute pancreatitis. Microvasc Res 2008; 76:114-23. [PMID: 18586042 DOI: 10.1016/j.mvr.2008.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Revised: 04/23/2008] [Accepted: 05/29/2008] [Indexed: 02/07/2023]
Abstract
The most successful approach for restoring normal long-term glucose homeostasis in type I diabetes mellitus is whole-organ pancreas transplantation. Graft pancreatitis is observed in up to 20% of patients and may lead to loss of the transplanted organ. Several pathophysiological events have been implicated in this form of pancreatitis. The most important cause of early graft pancreatitis is ischemia/reperfusion (I/R)-related disturbance of microvascular perfusion with subsequent hypoxic tissue damage. Recently, considerable evidence accumulated that, among a variety of other pathophysiological events, the activation of platelets can contribute to I/R injury in the course of acute pancreatitis experimentally and clinically. This review summarizes the events affecting platelet function and, therefore, pancreatic microcirculation leading to acute pancreatitis. Therapeutic approaches and own results are presented.
Collapse
Affiliation(s)
- Dirk Uhlmann
- 2nd Department of Surgery, University of Leipzig, Germany.
| | | | | | | |
Collapse
|
9
|
Braga MDM, Martins AMC, de Menezes DB, Barbosa PSF, Evangelista JSAM, Toyama MH, Toyama DO, Fonteles MC, Monteiro HSA. Purification and biological activity of the thrombin-like substance isolated from Bothrops insularis venom. Toxicon 2007; 49:329-38. [PMID: 17161857 DOI: 10.1016/j.toxicon.2006.10.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Revised: 10/17/2006] [Accepted: 10/18/2006] [Indexed: 11/21/2022]
Abstract
The venom of Bothrops insularis snake, known in Brazil as jararaca ilhoa, contains a variety of proteolytic enzymes such as a thrombin-like substance that is responsible for various pharmacological effects. B. insularis venom chromatography profile showed an elution of seven main fractions. The thrombin-like activity was detected in fractions I and III, the latter being subjected to two other chromatographic procedures, so to say DEAE and Hi Trap Benzamidine. The purity degree of this fraction was confirmed by analytical reverse phase HPLC, which displayed only one main fraction confirmed by SDS-PAGE constituting fraction III. About 5 microg of fraction III protein potentiated the secretion of insulin induced by 2.8 mM of glucose in rats isolated pancreatic beta-cells treated; the increase being around 3-fold higher than its respective control. B. insularis lectin (BiLec; 10 microg/mL) was also studied as to its effect on the renal function of isolated perfused rat kidneys with the use of six Wistar rats. BiLec increased perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF) and glomerular filtration rate (GFR). Sodium (%TNa+) and chloride tubular reabsorption (%TCl-) decreased at 120 min, without alteration in potassium transport. In conclusion, the thrombin-like substance isolated from B. insularis venom induced an increase in insulin secretion, in vitro, and transiently altered vascular, glomerular and tubular parameters in the isolated rat kidney.
Collapse
|
10
|
Long DA, Newaz MA, Prabhakar SS, Price KL, Truong LD, Feng L, Mu W, Oyekan AO, Johnson RJ. Loss of nitric oxide and endothelial-derived hyperpolarizing factor-mediated responses in aging. Kidney Int 2005; 68:2154-63. [PMID: 16221214 DOI: 10.1111/j.1523-1755.2005.00671.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Aging has considerable structural and functional effects on the vascular system of the kidney. One such effect is an alteration in vascular tone which potentially will initiate renal damage. Vascular tone is determined by the balance between vasoconstrictors and vasodilators. Therefore, we hypothesized that aging attenuates vasodilatory responses in the kidney. These changes may be mediated by a loss of nitric oxide and endothelial-derived hyperpolarizing factor (EDHF). METHODS The systemic and renal responses of nitric oxide and EDHF were investigated in aging (18 months old) and young (3 months old) Sprague-Dawley rats. RESULTS We demonstrated a general loss of vasodilatory responses in the aging kidney. In addition, nitric oxide levels were reduced in the serum and kidney cortex of aging versus young animals, although this was not accompanied with a loss of endothelial nitric oxide synthase (eNOS) protein in the kidney cortex. Aging animals also exhibited a loss in EDHF-mediated vasodilation following stimulation with either acetylcholine or bradykinin in the isolated perfused kidney. CONCLUSION These findings indicate that not only a defect in the nitric oxide pathway, but also a loss of EDHF-mediated responses may be responsible for impaired vasodilation in the aging kidney. This may result in enhanced vasoconstrictive responses in aging which potentially will cause renal damage and ultimately a loss in glomerular filtration rate (GFR).
Collapse
Affiliation(s)
- David A Long
- Section of Nephrology, Hypertension and Transplantation, University of Florida, Gainesville, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Morio Y, Carter EP, Oka M, McMurtry IF. EDHF-mediated vasodilation involves different mechanisms in normotensive and hypertensive rat lungs. Am J Physiol Heart Circ Physiol 2003; 284:H1762-70. [PMID: 12521932 DOI: 10.1152/ajpheart.00831.2002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of endothelium-derived hyperpolarizing factor (EDHF) in regulating the pulmonary circulation and the participation of cytochrome P-450 (CYP450) activity and gap junction intercellular communication in EDHF-mediated pulmonary vasodilation are unclear. We tested whether tonic EDHF activity regulated pulmonary vascular tone and examined the mechanism of EDHF-mediated pulmonary vasodilation induced by thapsigargin in salt solution-perfused normotensive and hypoxia-induced hypertensive rat lungs. After blockade of both cyclooxygenase and nitric oxide synthase, inhibition of EDHF with charybdotoxin plus apamin did not affect either normotensive or hypertensive vascular tone or acute hypoxic vasoconstriction but abolished thapsigargin vasodilation in both groups of lungs. The CYP450 inhibitors 7-ethoxyresorufin and sulfaphenazole and the gap junction inhibitor palmitoleic acid, but not 18alpha-glycyrrhetinic acid, inhibited thapsigargin vasodilation in normotensive lungs. None of these agents inhibited the vasodilation in hypertensive lungs. Thus tonic EDHF activity does not regulate either normotensive or hypertensive pulmonary vascular tone or acute hypoxic vasoconstriction. Whereas thapsigargin-induced EDHF-mediated vasodilation in normotensive rat lungs involves CYP450 activity and might act through gap junctions, the mechanism of vasodilation is apparently different in hypertensive lungs.
Collapse
Affiliation(s)
- Yoshiteru Morio
- Cardiovascular Pulmonary Research Laboratory, Department of Medicine, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, Denver, CO 80262, USA
| | | | | | | |
Collapse
|
12
|
Shigematsu S, Ishida S, Gute DC, Korthuis RJ. Bradykinin-induced proinflammatory signaling mechanisms. Am J Physiol Heart Circ Physiol 2002; 283:H2676-86. [PMID: 12388246 DOI: 10.1152/ajpheart.00538.2002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intravital microscopic techniques were used to examine the mechanisms underlying bradykinin-induced leukocyte/endothelial cell adhesive interactions (LECA) and venular protein leakage (VPL) in single postcapillary venules of the rat mesentery. The effects of bradykinin superfusion to increase LECA and VPL were prevented by coincident topical application of either a bradykinin-B(2) receptor antagonist, a cell-permeant superoxide dismutase (SOD) mimetic or antioxidant, or inhibitors of cytochrome P-450 epoxygenase (CYPE) or protein kinase C (PKC) but not by concomitant treatment with either SOD, a mast cell stabilizer, or inhibitors of nitric oxide synthase, cyclooxygenase, xanthine oxidase, NADPH oxidase, or platelet-activating factor. Immunoneutralizing P-selectin or intercellular adhesion molecule-1 (ICAM-1) completely prevented bradykinin-induced leukocyte adhesion and emigration but did not affect VPL. On the other hand, stabilization of F-actin with phalloidin prevented bradykinin-induced leukocyte emigration and VPL but did not alter leukocyte adhesion. These data indicate that bradykinin induces LECA in rat mesenteric venules via a B(2)-receptor-initiated, CYPE-, oxidant- and PKC-mediated, P-selectin- and ICAM-1-dependent mechanism. Bradykinin also produced VPL, an effect that was initiated by stimulation of B(2) receptors and involved CYPE and PKC activation, oxidant generation, and cytoskeletal reorganization but was independent of leukocyte adherence and emigration.
Collapse
Affiliation(s)
- Sakuji Shigematsu
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport 71130, USA
| | | | | | | |
Collapse
|