1
|
Cano IP, Dionisio TJ, Cestari TM, Calvo AM, Colombini-Ishikiriama BL, Faria FAC, Siqueira WL, Santos CF. Losartan and isoproterenol promote alterations in the local renin-angiotensin system of rat salivary glands. PLoS One 2019; 14:e0217030. [PMID: 31116771 PMCID: PMC6530859 DOI: 10.1371/journal.pone.0217030] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 05/02/2019] [Indexed: 12/18/2022] Open
Abstract
Renin-angiotensin system (RAS) systemically or locally collaborates with tissue homeostasis, growth and development, which has been extensively studied for its pharmacological implications. This study was primarily aimed at finding and characterizing local RAS in rat parotid, sublingual and submandibular glands. It was also hypothesized that vasoactive drugs could affect the expression of RAS targets, as well as saliva flow and its composition. Therefore, another objective of this study was to compare the effects of losartan (angiotensin II receptor blocker) and isoproterenol (β-adrenergic receptor agonist). Forty-one Wistar rats were divided into three groups and administered a daily intraperitoneal dose of saline, losartan or isoproterenol solutions for one week. The following RAS targets were studied using qPCR: renin (REN), angiotensinogen (AGT), angiotensin converting enzyme (ACE), ACE-2, elastase-2 (ELA-2), AT1-a and MAS receptors, using RPL-13 as a reference gene. Morphology of glands was analyzed by immunohistochemistry using REN, ACE, ACE-2, AT1, AT2 and MAS antibodies. The volume and total protein content of saliva were measured. Our results revealed that ACE, ACE-2, AT1-a, AT2 and MAS receptors were expressed in all salivary gland samples, but REN and ELA-2 were absent. Losartan decreased mRNA expression of RAS targets in parotid (MAS) and submandibular glands (ACE and both AT receptors), without affecting morphological alterations, and significantly decreased saliva and total protein secretions. Isoproterenol treatment affected gene expression profiles in parotid (ACE, ACE-2, AT1-a, MAS, AGT), and submandibular (ACE, AT2, AGT) glands, thus promoting acinar hypertrophy in serous acini, without significant changes in salivary flow or total protein content. These drugs affected mainly acini, followed by duct systems and myoepithelial cells, whereas blood vessels were not affected. In conclusion, there is a local RAS in major rat salivary glands and losartan, an angiotensin II receptor blocker, affected not only the RAS-target gene expression but also decreased salivary flow and total protein content.
Collapse
Affiliation(s)
- Isadora Prado Cano
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Thiago José Dionisio
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Tânia Mary Cestari
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Adriana Maria Calvo
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | | | - Flávio Augusto Cardoso Faria
- Department of Biochemistry and School of Dentistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | - Walter Luiz Siqueira
- Department of Biochemistry and School of Dentistry, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Canada
| | - Carlos Ferreira Santos
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
- * E-mail:
| |
Collapse
|
2
|
Becari C, Durand MT, Guimaraes AO, Lataro RM, Prado CM, de Oliveira M, Candido SCO, Pais P, Ribeiro MS, Bader M, Pesquero JB, Salgado MCO, Salgado HC. Elastase-2, a Tissue Alternative Pathway for Angiotensin II Generation, Plays a Role in Circulatory Sympathovagal Balance in Mice. Front Physiol 2017; 8:170. [PMID: 28386233 PMCID: PMC5363176 DOI: 10.3389/fphys.2017.00170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 03/07/2017] [Indexed: 12/26/2022] Open
Abstract
In vitro and ex vivo experiments indicate that elastase-2 (ELA-2), a chymotrypsin-serine protease elastase family member 2A, is an alternative pathway for angiotensin II (Ang II) generation. However, the role played by ELA-2 in vivo is unclear. We examined ELA-2 knockout (ELA-2KO) mice compared to wild-type (WT) mice and determined whether ELA-2 played a role in hemodynamics [arterial pressure (AP) and heart rate (HR)], cardiocirculatory sympathovagal balance and baroreflex sensitivity. The variability of systolic arterial pressure (SAP) and pulse interval (PI) for evaluating autonomic modulation was examined for time and frequency domains (spectral analysis), whereas a symbolic analysis was also used to evaluate PI variability. In addition, baroreflex sensitivity was examined using the sequence method. Cardiac function was evaluated echocardiographically under anesthesia. The AP was normal whereas the HR was reduced in ELA-2KO mice (425 ± 17 vs. 512 ± 13 bpm from WT). SAP variability and baroreflex sensitivity were similar in both strains. The LF power from the PI spectrum (33.6 ± 5 vs. 51.8 ± 4.8 nu from WT) and the LF/HF ratio (0.60 ± 0.1 vs. 1.45 ± 0.3 from WT) were reduced, whereas the HF power was increased (66.4 ± 5 vs. 48.2 ± 4.8 nu from WT) in ELA-2KO mice, indicating a shift toward parasympathetic modulation of HR. Echocardiographic examination showed normal fractional shortening and an ejection fraction in ELA-2KO mice; however, the cardiac output, stroke volume, and ventricular size were reduced. These findings provide the first evidence that ELA-2 acts on the sympathovagal balance of the heart, as expressed by the reduced sympathetic modulation of HR in ELA-2KO mice.
Collapse
Affiliation(s)
- Christiane Becari
- Department of Physiology, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil; Department of Pharmacology, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil; Department of Cardiovascular Diseases, Mayo ClinicRochester, MN, USA
| | - Marina T Durand
- Department of Physiology, Ribeirão Preto Medical School, University of São PauloRibeirão Preto, Brazil; Department of Medicine, University of Ribeirão PretoRibeirão Preto, Brazil
| | - Alessander O Guimaraes
- Max Delbruck Center for Molecular MedicineBerlin, Germany; Department of Biophysics, Federal University of São PauloSão Paulo, Brazil
| | - Renata M Lataro
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Cibele M Prado
- Department of Pathology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Mauro de Oliveira
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Sarai C O Candido
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Paloma Pais
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Mauricio S Ribeiro
- Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Michael Bader
- Max Delbruck Center for Molecular MedicineBerlin, Germany; Berlin Institute of Health, Charité-University Medicine BerlinBerlin, Germany; German Center for Cardiovascular Research, Partner Site BerlinBerlin, Germany
| | - Joao B Pesquero
- Department of Biophysics, Federal University of São Paulo São Paulo, Brazil
| | - Maria C O Salgado
- Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| | - Helio C Salgado
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo Ribeirão Preto, Brazil
| |
Collapse
|
3
|
Becari C, Silva MAB, Durand MT, Prado CM, Oliveira EB, Ribeiro MS, Salgado HC, Salgado MCO, Tostes RC. Elastase-2, an angiotensin II-generating enzyme, contributes to increased angiotensin II in resistance arteries of mice with myocardial infarction. Br J Pharmacol 2017; 174:1104-1115. [PMID: 28222221 DOI: 10.1111/bph.13755] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/08/2017] [Accepted: 02/11/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE Angiotensin II (Ang II), whose generation largely depends on angiotensin-converting enzyme (ACE) activity, mediates most of the renin-angiotensin-system (RAS) effects. Elastase-2 (ELA-2), a chymotrypsin-serine protease elastase family member 2A, alternatively generates Ang II in rat arteries. Myocardial infarction (MI) leads to intense RAS activation, but mechanisms involved in Ang II-generation in resistance arteries are unknown. We hypothesized that ELA-2 contributes to vascular Ang II generation and cardiac damage in mice subjected to MI. EXPERIMENTAL APPROACH Concentration-effect curves to Ang I and Ang II were performed in mesenteric resistance arteries from male wild type (WT) and ELA-2 knockout (ELA-2KO) mice subjected to left anterior descending coronary artery ligation (MI). KEY RESULTS MI size was similar in WT and ELA-2KO mice. Ejection fraction and fractional shortening after MI similarly decreased in both strains. However, MI decreased stroke volume and cardiac output in WT, but not in ELA-2KO mice. Ang I-induced contractions increased in WT mice subjected to MI (MI-WT) compared with sham-WT mice. No differences were observed in Ang I reactivity between arteries from ELA-2KO and ELA-2KO subjected to MI (MI-ELA-2KO). Ang I contractions increased in arteries from MI-WT versus MI-ELA-2KO mice. Chymostatin attenuated Ang I-induced vascular contractions in WT mice, but did not affect Ang I responses in ELA-2KO arteries. CONCLUSIONS AND IMPLICATIONS These results provide the first evidence that ELA-2 contributes to increased Ang II formation in resistance arteries and modulates cardiac function after MI, implicating ELA-2 as a key player in ACE-independent dysregulation of the RAS.
Collapse
Affiliation(s)
- Christiane Becari
- Departments of Pharmacology, University of Sao Paulo, Ribeirao Preto, SP, Brazil.,Physiology, University of Sao Paulo, Ribeirao Preto, SP, Brazil.,Department of Cardiovascular Diseases, Mayo Clinic, Rochester, MN, USA
| | - Marcondes A B Silva
- Departments of Pharmacology, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Marina T Durand
- Physiology, University of Sao Paulo, Ribeirao Preto, SP, Brazil.,Department of Medicine, University of Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - Cibele M Prado
- Pathology and Legal Medicine, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Eduardo B Oliveira
- Biochemistry and Immunology, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Mauricio S Ribeiro
- Surgery and Anatomy, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | - Helio C Salgado
- Physiology, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| | | | - Rita C Tostes
- Departments of Pharmacology, University of Sao Paulo, Ribeirao Preto, SP, Brazil
| |
Collapse
|
4
|
Santos CF, Morandini AC, Dionísio TJ, Faria FA, Lima MC, Figueiredo CM, Colombini-Ishikiriama BL, Sipert CR, Maciel RP, Akashi AP, Souza GP, Garlet GP, Rodini CO, Amaral SL, Becari C, Salgado MC, Oliveira EB, Matus I, Didier DN, Greene AS. Functional Local Renin-Angiotensin System in Human and Rat Periodontal Tissue. PLoS One 2015; 10:e0134601. [PMID: 26244896 PMCID: PMC4526652 DOI: 10.1371/journal.pone.0134601] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 07/12/2015] [Indexed: 12/28/2022] Open
Abstract
The initiation or progression of periodontitis might involve a local renin-angiotensin system (RAS) in periodontal tissue. The aim of this study was to further characterize the local RAS in human and rat periodontal tissues between healthy and periodontally-affected tissue. Components of the RAS were investigated using in vitro, ex vivo and in vivo experiments involving both human and Wistar rat periodontium. Although not upregulated when challenged with P. gingivalis-lipopolysaccharide, human gingival and periodontal ligament fibroblasts expressed RAS components. Likewise, healthy and inflamed human gingiva expressed RAS components, some of which were shown to be functional, yet no differences in expression were found between healthy and diseased gingiva. However, in inflamed tissue the immunoreactivity was greater for the AT1R compared to AT2R in fibroblasts. When compared to healthy tissue, ACE activity was increased in human gingiva from volunteers with gingivitis. Human-gingiva homogenates generated Ang II, Ang 1-9 and Ang 1-7 when incubated with precursors. In gingiva homogenates, Ang II formation from Ang I was nearly abolished only when captopril and chymostatin were combined. Ang 1-7 formation was significantly greater when human gingiva homogenates were incubated with chymostatin alone compared to incubation without any inhibitor, only captopril, or captopril and chymostatin. In rat gingiva, RAS components were also found; their expression was not different between healthy and experimentally induced periodontitis (EP) groups. However, renin inhibition (aliskiren) and an AT1R antagonist (losartan) significantly blocked EP-alveolar-bone loss in rats. Collectively, these data are consistent with the hypothesis that a local RAS system is not only present but is also functional in both human and rat periodontal tissue. Furthermore, blocking AT1R and renin can significantly prevent periodontal bone loss induced by EP in rats.
Collapse
Affiliation(s)
- Carlos F. Santos
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
- * E-mail:
| | - Ana C. Morandini
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Thiago J. Dionísio
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Flávio A. Faria
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Marta C. Lima
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Caio M. Figueiredo
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | | | - Carla R. Sipert
- Department of Restorative Dentistry, School of Dentistry, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Rubens P. Maciel
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Ana P. Akashi
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Gabriela P. Souza
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Gustavo P. Garlet
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Camila O. Rodini
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Sandra L. Amaral
- Department of Physical Education, Science Faculty, São Paulo State University, Bauru, São Paulo, Brazil
| | - Christiane Becari
- School of Medicine of Ribeirão Preto, Riberão Preto, University of São Paulo, Riberão Preto, São Paulo, Brazil
| | - Maria C. Salgado
- School of Medicine of Ribeirão Preto, Riberão Preto, University of São Paulo, Riberão Preto, São Paulo, Brazil
| | - Eduardo B. Oliveira
- School of Medicine of Ribeirão Preto, Riberão Preto, University of São Paulo, Riberão Preto, São Paulo, Brazil
| | - Isaac Matus
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Daniela N. Didier
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Andrew S. Greene
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| |
Collapse
|
5
|
Santos CFD, Sakai VT, Machado MADAM, Schippers DN, Greene AS. Reverse transcription and polymerase chain reaction: principles and applications in dentistry. J Appl Oral Sci 2012; 12:1-11. [PMID: 21365144 DOI: 10.1590/s1678-77572004000100002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Various molecular biology techniques have become available in the last few years. One of the most revolutionary of these techniques regarding nucleic acid analysis is the polymerase chain reaction (PCR), which was first described in 1985. This method relies on the exponential amplification of specific DNA fragments, resulting in millions of copies that can serve as templates for different kinds of analyses. PCR can be preceded by a reverse transcription (RT) reaction in order to produce cDNA from RNA (RT-PCR). RT-PCR provides the possibility to assess gene transcription in cells or tissues. PCR and RT-PCR techniques have been instrumental in dental research, and show potential to be used for diagnosis as well as for treatment and prevention of many diseases (dental caries, periodontal disease, endodontic infections and oral cancer). Compared to other traditional methodologies, PCR and RT-PCR show many advantages including high specificity, sensitivity, and speed. Since PCR and RT-PCR are relatively new techniques and are not available to most students and professionals involved with dentistry, the aim of this work is to present the details of these techniques as well as dental literature reports in which they were used.
Collapse
|
6
|
Becari C, Oliveira EB, Salgado MCO. Alternative pathways for angiotensin II generation in the cardiovascular system. Braz J Med Biol Res 2011; 44:914-9. [PMID: 21956534 DOI: 10.1590/s0100-879x2011007500093] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 07/08/2011] [Indexed: 12/27/2022] Open
Abstract
The classical renin-angiotensin system (RAS) consists of enzymes and peptides that regulate blood pressure and electrolyte and fluid homeostasis. Angiotensin II (Ang II) is one of the most important and extensively studied components of the RAS. The beneficial effects of angiotensin converting enzyme (ACE) inhibitors in the treatment of hypertension and heart failure, among other diseases, are well known. However, it has been reported that patients chronically treated with effective doses of these inhibitors do not show suppression of Ang II formation, suggesting the involvement of pathways alternative to ACE in the generation of Ang II. Moreover, the finding that the concentration of Ang II is preserved in the kidney, heart and lungs of mice with an ACE deletion indicates the important role of alternative pathways under basal conditions to maintain the levels of Ang II. Our group has characterized the serine protease elastase-2 as an alternative pathway for Ang II generation from Ang I in rats. A role for elastase-2 in the cardiovascular system was suggested by studies performed in heart and conductance and resistance vessels of normotensive and spontaneously hypertensive rats. This mini-review will highlight the pharmacological aspects of the RAS, emphasizing the role of elastase-2, an alternative pathway for Ang II generation.
Collapse
Affiliation(s)
- C Becari
- Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brasil.
| | | | | |
Collapse
|
7
|
Becari C, Teixeira FR, Oliveira EB, Salgado MCO. Angiotensin-converting enzyme inhibition augments the expression of rat elastase-2, an angiotensin II-forming enzyme. Am J Physiol Heart Circ Physiol 2011; 301:H565-70. [PMID: 21602471 DOI: 10.1152/ajpheart.00534.2010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mounting evidence suggest that tissue levels of angiotensin (ANG) II are maintained in animals submitted to chronic angiotensin-converting enzyme (ACE) inhibitor treatment. We examined the expression levels of transcripts for elastase-2, a chymostatin-sensitive serine protease identified as the alternative pathway for ANG II generation from ANG I in the rat vascular tissue and the relative role of ACE-dependent and -independent pathways in generating ANG II in the rat isolated carotid artery rings of spontaneously hypertensive rats (SHR) and Wistar normotensive rats (WNR) treated with enalapril for 7 days. Enalapril treatment decreased blood pressure of SHR only and resulted in significantly more elastase-2 mRNA expression in carotid artery of both enalapril-treated WNR and SHR. Captopril induced a comparable rightward shift of concentration-response curves to ANG I in vehicle and enalapril-treated rats, although this effect was of lesser magnitude in SHR group. Chymostatin induced a rightward shift of the dose response to ANG I in vehicle-treated and a decrease in maximal effect of 22% in enalapril-treated WNR group. Maximal response induced by ANG I was remarkably reduced by chymostatin in enalapril-treated SHR carotid artery (by 80%) compared with controls (by 23%). Our data show that chronic ACE inhibition was associated with augmented functional role of non-ACE pathway in generating ANG II and increased elastase-2 gene expression, suggesting that this protease may contribute as an alternative pathway for ANG II generation when ACE is inhibited in the rat vascular tissue.
Collapse
Affiliation(s)
- Christiane Becari
- Department of Pharmacology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | | | | | | |
Collapse
|
8
|
Bispo-da-Silva LB, Sivieri DO, Prado CM, Becari C, Stuckert-Seixas SR, Pereira HJV, Rossi MA, Oliveira EB, Salgado MCO. Cardiac mast cell proteases do not contribute to the regulation of the rat coronary vascular responsiveness to arterial delivered angiotensin I and II. Vascul Pharmacol 2010; 53:22-7. [PMID: 20307688 DOI: 10.1016/j.vph.2010.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 02/10/2010] [Accepted: 03/08/2010] [Indexed: 10/19/2022]
Abstract
Cardiac mast cells (MC) are apposed to capillaries within the heart and release renin and proteases capable of metabolizing angiotensins (Ang). Therefore, we hypothesized that mast cell degranulation could alter the rat coronary vascular responsiveness to the arterial delivered Ang I and Ang II, taking into account carboxypeptidase and chymase-1 activities. Hearts from animals that were either pretreated or not with systemic injection of the secretagogue compound 48/80 were isolated and mounted on a Langendorff apparatus to investigate coronary reactivity. The proteolytic activity of the cardiac perfusate from isolated hearts, pretreated or not with the secretagogue, toward Ang I and tetradecapeptide renin substrate was analyzed by HPLC. Coronary vascular reactivity to peptides was not affected by compound 48/80 pretreatment, despite the extensive amount of cardiac MC degranulation. Cardiac MC activation did not modify the generation of both Ang II and Ang 5-10 from Ang I by cardiac perfusate, activities that could be ascribed to MC carboxypeptidase and chymase-1, respectively. An aliskiren-resistant Ang I-forming activity was increased in perfusates from secretagogue-treated hearts. Thus, cardiac MC proteases capable of metabolizing angiotensins do not affect rat coronary reactivity to arterial delivered Ang I and II.
Collapse
Affiliation(s)
- Luiz B Bispo-da-Silva
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Santos CF, Akashi AE, Dionísio TJ, Sipert CR, Didier DN, Greene AS, Oliveira SHP, Pereira HJV, Becari C, Oliveira EB, Salgado MCO. Characterization of a local renin-angiotensin system in rat gingival tissue. J Periodontol 2009; 80:130-9. [PMID: 19228099 DOI: 10.1902/jop.2009.080264] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND The systemic renin-angiotensin system (RAS) promotes the plasmatic production of angiotensin (Ang) II, which acts through interaction with specific receptors. There is growing evidence that local systems in various tissues and organs are capable of generating angiotensins independently of circulating RAS. The aims of this study were to investigate the expression and localization of RAS components in rat gingival tissue and evaluate the in vitro production of Ang II and other peptides catalyzed by rat gingival tissue homogenates incubated with different Ang II precursors. METHODS Reverse transcription-polymerase chain reaction assessed mRNA expression. Immunohistochemical analysis aimed to detect and localize renin. A standardized fluorimetric method with tripeptide hippuryl-histidyl-leucine was used to measure tissue angiotensin-converting enzyme (ACE) activity, whereas high performance liquid chromatography showed products formed after the incubation of tissue homogenates with Ang I or tetradecapeptide renin substrate (TDP). RESULTS mRNA for renin, angiotensinogen, ACE, and Ang II receptors (AT(1a), AT(1b), and AT(2)) was detected in gingival tissue; cultured gingival fibroblasts expressed renin, angiotensinogen, and AT(1a) receptor. Renin was present in the vascular endothelium and was intensely expressed in the epithelial basal layer of periodontally affected gingival tissue. ACE activity was detected (4.95 +/- 0.89 nmol histidyl-leucine/g/minute). When Ang I was used as substrate, Ang 1-9 (0.576 +/- 0.128 nmol/mg/minute), Ang II (0.066 +/- 0.008 nmol/mg/minute), and Ang 1-7 (0.111 +/- 0.017 nmol/mg/minute) were formed, whereas these same peptides (0.139 +/- 0.031, 0.206 +/- 0.046, and 0.039 +/- 0.007 nmol/mg/minute, respectively) and Ang I (0.973 +/- 0.139 nmol/mg/minute) were formed when TDP was the substrate. CONCLUSION Local RAS exists in rat gingival tissue and is capable of generating Ang II and other vasoactive peptides in vitro.
Collapse
Affiliation(s)
- C F Santos
- Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Oliveira TM, Sakai VT, Machado MAAM, Dionísio TJ, Cestari TM, Taga R, Amaral SL, Santos CF. COX-2 inhibition decreases VEGF expression and alveolar bone loss during the progression of experimental periodontitis in rats. J Periodontol 2008; 79:1062-9. [PMID: 18533784 DOI: 10.1902/jop.2008.070411] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Vascular endothelial growth factor (VEGF) is a macromolecule of importance in inflammation that has been implicated in periodontitis. The aims of this study were to investigate VEGF expression during the progression of periodontal disease and to evaluate the effect of a preferential cyclooxygenase (COX)-2 inhibitor meloxicam on VEGF expression and alveolar bone loss in experimentally induced periodontitis. METHODS A total of 120 Wistar rats were randomly separated into groups 1 (control) and 2 (meloxicam, 3 mg/kg/day, intraperitoneally, for 3, 7, 14, or 30 days). Silk ligatures were placed at the gingival margin level of the lower right first molar of all rats. VEGF expression was assessed by reverse transcription-polymerase chain reaction (RT-PCR), Western blot (WB), and immunohistochemical (IHC) analyses. The hemiarcades were processed for histopathologic analysis. RT-PCR and WB results were submitted to analysis of variance, the Tukey test, and Pearson correlation analysis (P <0.05). RESULTS A reduction in alveolar bone resorption was observed in the meloxicam-treated group compared to the control group at all periods studied. There was a positive correlation between COX-2 mRNA and VEGF mRNA in the gingival tissues and periodontal disease (R = 0.80; P = 0.026). Meloxicam significantly reduced the increased mRNA VEGF expression in diseased tissues after 14 days of treatment (P = 0.023). Some alterations in VEGF receptor 1 mRNA expression were observed, but these were not statistically significant. VEGF protein expression in WB experiments was significantly higher in diseased sites compared to healthy sites (P <0.05). After 14 days of treatment with meloxicam, an important decrease in VEGF protein expression was detected in diseased tissues (P = 0.08). Qualitative IHC analysis revealed that VEGF protein expression was higher in diseased tissues and decreased in tissues from rats treated with meloxicam. CONCLUSIONS The present data suggest an important role for VEGF in the progression of periodontal disease. Systemic therapy with meloxicam can modify the progression of experimentally induced periodontitis in rats by reducing VEGF expression and alveolar bone loss.
Collapse
Affiliation(s)
- Thais M Oliveira
- Department of Pediatric Dentistry, Orthodontics and Community Health, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Morphologic evaluation and expression of matrix metalloproteinases-2 and 9 and nitric oxide during experimental periodontal disease in rat. J Mol Histol 2008; 39:275-82. [PMID: 18247145 DOI: 10.1007/s10735-008-9163-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2007] [Accepted: 01/16/2008] [Indexed: 10/22/2022]
Abstract
The immunopathologic and inflammatory mechanisms involved in periodontal disease (PD) include the participation of host resident, inflammatory cells and chemical mediators. Metalloproteinases (MMPs) and nitric oxide (NO) play essential role in extracellular matrix turnover of periodontal tissue destruction. In this study, by means of RT-PCR through semi-quantitative densitometric scanning methods, the expression of MMPs -2 and -9 and inducible NO synthase (iNOS) was temporally and spatially investigated during the destructive mechanisms of experimentally induced PD in rats. Samples from different periods were microscopically analyzed and compared with the contralateral side (control). Our results showed significant expression of MMP-9 and iNOS in tissues affected by PD, as compared with controls, three days after PD induction, simultaneously with the beginning of alveolar bone loss. At 7 days post induction, only the MMP-9 mRNA presented a significantly higher expression, as compared with the respective controls. Thus, in the rat ligature-induced PD, MMP-9 and iNOS might importantly participate in the early stages of the disease, including inflammatory cell migration, tissue destruction and alveolar bone resorption. Also, we may suggest that the exuberant presence of PMNs may be related to the important expression of iNOS and MMP-9 found at 3 days post induction.
Collapse
|
12
|
Oliveira EB, Souza LL, Sivieri DO, Bispo-da-Silva LB, Pereira HJV, Costa-Neto CM, Sousa MV, Salgado MCO. Carboxypeptidase B and other kininases of the rat coronary and mesenteric arterial bed perfusates. Am J Physiol Heart Circ Physiol 2007; 293:H3550-7. [PMID: 17906107 DOI: 10.1152/ajpheart.00784.2007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We describe the enzymes that constitute the major bradykinin (BK)-processing pathways in the perfusates of mesenteric arterial bed (MAB) and coronary vessels isolated from Wistar normotensive rats (WNR) and spontaneously hypertensive rats. The contribution of particular proteases to BK degradation was revealed by the combined analysis of fragments generated during incubation of BK with representative perfusate samples and the effect of selective inhibitors on the respective reactions. Marked differences were seen among the perfusates studied; MAB secretes, per minute of perfusion, kininase activity capable of hydrolyzing approximately 300 pmol of BK/min, which is approximately 250-fold larger amount on a per unit time basis than that of its coronary counterpart. BK degradation in the coronary perfusate seems to be mediated by ANG I-converting enzyme, neutral endopeptidase 24.11-like enzyme, and a dl-2-mercaptomethyl-3-guanidinoethylthiopropanoic acid-sensitive basic carboxypeptidase; coronary perfusate of WNR contains an additional BK-degrading enzyme whose specificity resembles that of neurolysin or thimet oligopeptidase. Diversely, a des-Arg(9)-BK-forming enzyme, responsible for nearly all of the kininase activity of MAB perfusates of WNR and spontaneously hypertensive rats, could be purified by a procedure that involved affinity chromatography over potato carboxypeptidase inhibitor-Sepharose column and shown to be structurally identical to rat pancreatic carboxypeptidase B (CPB). Comparable levels of CPB mRNA expression were observed in pancreas, liver, mesentery, and kidney, but very low levels were detected in lung, heart, aorta, and carotid artery. In conclusion, distinct BK-processing pathways operate in the perfusates of rat MAB and coronary bed, with a substantial participation of a des-Arg(9)-BK-forming enzyme identical to pancreatic CPB.
Collapse
Affiliation(s)
- Eduardo B Oliveira
- Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto-USP, 14049-900 Ribeirão Preto, SP, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Lavrentyev EN, Estes AM, Malik KU. Mechanism of high glucose induced angiotensin II production in rat vascular smooth muscle cells. Circ Res 2007; 101:455-64. [PMID: 17626897 DOI: 10.1161/circresaha.107.151852] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Angiotensin II (Ang II), a circulating hormone that can be synthesized locally in the vasculature, has been implicated in diabetes-associated vascular complications. This study was conducted to determine whether high glucose (HG) (approximately 23.1 mmol/L), a diabetic-like condition, stimulates Ang II generation and the underlying mechanism of its production in rat vascular smooth muscle cells. The contribution of various enzymes involved in Ang II generation was investigated by silencing their expression with small interfering RNA in cells exposed to normal glucose (approximately 4.1 mmol/L) and HG. Angiotensin I (Ang I) was generated from angiotensinogen by cathepsin D in the presence of normal glucose or HG. Although HG did not affect the rate of angiotensinogen conversion, it decreased expression of angiotensin-converting enzyme (ACE), downregulated ACE-dependent Ang II generation, and upregulated rat vascular chymase-dependent Ang II generation. The ACE inhibitor captopril reduced Ang II levels in the media by 90% in the presence of normal glucose and 19% in HG, whereas rat vascular chymase silencing reduced Ang II production in cells exposed to HG but not normal glucose. The glucose transporter inhibitor cytochalasin B, the aldose reductase inhibitor alrestatin, and the advanced glycation end product formation inhibitor aminoguanidine attenuated HG-induced Ang II generation. HG caused a transient increase in extracellular signal-regulated kinase (ERK)1/2 phosphorylation, and ERK1/2 inhibitors reduced Ang II accumulation by HG. These data suggest that polyol pathway metabolites and AGE can stimulate rat vascular chymase activity via ERK1/2 activation and increase Ang II production. In addition, decreased Ang II degradation, which, in part, could be attributable to a decrease in angiotensin-converting enzyme 2 expression observed in HG, contributes to increased accumulation of Ang II in vascular smooth muscle cells by HG.
Collapse
MESH Headings
- Angiotensin I/genetics
- Angiotensin I/metabolism
- Angiotensin II/genetics
- Angiotensin II/metabolism
- Animals
- Cathepsin D/genetics
- Cathepsin D/metabolism
- Cells, Cultured
- Chymases/genetics
- Chymases/metabolism
- Dose-Response Relationship, Drug
- Enzyme Inhibitors/pharmacology
- Gene Expression Regulation/drug effects
- Glucose/pharmacology
- Male
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Peptidyl-Dipeptidase A/genetics
- Peptidyl-Dipeptidase A/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Small Interfering/pharmacology
- Rats
- Rats, Sprague-Dawley
- Tissue Plasminogen Activator/genetics
- Tissue Plasminogen Activator/metabolism
Collapse
Affiliation(s)
- Eduard N Lavrentyev
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | | | | |
Collapse
|
14
|
Carneiro-Ramos MS, Diniz GP, Almeida J, Vieira RLP, Pinheiro SVB, Santos RA, Barreto-Chaves MLM. Cardiac angiotensin II type I and type II receptors are increased in rats submitted to experimental hypothyroidism. J Physiol 2007; 583:213-23. [PMID: 17540701 PMCID: PMC2277238 DOI: 10.1113/jphysiol.2007.134080] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This study assessed the behaviour of angiotensin II (Ang II) receptors in an experimental hypothyroidism model in male Wistar rats. Animals were subjected to thyroidectomy and resting for 14 days. The alteration of cardiac mass was evaluated by total heart weight (HW), right ventricle weight (RVW), left ventricle weight (LVW), ratio of HW, RVW and LVW to body weight (BW) and atrial natriuretic factor (ANF) expression. Cardiac and plasma Ang II levels and serum T3 and T4 were determined. The mRNA and protein levels of Ang II receptors were investigated by RT-PCR and Western blotting, respectively. Functional analyses were performed using binding assays. T3 and T4 levels and the haemodynamic parameters confirmed the hypothyroid state. HW/BW, RVW/BW and LVW/BW ratios and the ANF expression were lower than those of control animals. No change was observed in cardiac or plasma Ang II levels. Both AT1/AT2 mRNA and protein levels were increased in the heart of hypothyroid animals due to a significant increase of these receptors in the RV. Experiments performed in cardiomyocytes showed a direct effect promoted by low thyroid hormone levels upon AT1 and AT2 receptors, discarding possible influence of haemodynamic parameters. Functional assays showed that both receptors are able to bind Ang II. Herein, we have identified, for the first time, a close and direct relation of elevated Ang II receptor levels in hypothyroidism. Whether the increase in these receptors in hypothyroidism is an alternative mechanism to compensate the atrophic state of heart or whether it may represent a potential means to the progression of heart failure remains unknown.
Collapse
MESH Headings
- Angiotensin II/metabolism
- Animals
- Atrial Natriuretic Factor
- Blood Pressure/physiology
- Cells, Cultured
- Gene Expression Regulation
- Hypothyroidism/metabolism
- Hypothyroidism/pathology
- Male
- Myocardium/metabolism
- Myocardium/pathology
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Random Allocation
- Rats
- Rats, Wistar
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 2/metabolism
- Thyroid Hormones/blood
- Thyroidectomy
Collapse
Affiliation(s)
- M S Carneiro-Ramos
- Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-900, Brazil
| | | | | | | | | | | | | |
Collapse
|
15
|
Sivieri DO, Bispo-da-Silva LB, Oliveira EB, Resende AC, Salgado MCO. Potentiation of bradykinin effect by angiotensin-converting enzyme inhibition does not correlate with angiotensin-converting enzyme activity in the rat mesenteric arteries. Hypertension 2007; 50:110-5. [PMID: 17470724 DOI: 10.1161/hypertensionaha.106.085761] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiotensin-converting enzyme (kininase II [ACE]) inhibitors are capable of potentiating bradykinin (BK) effects by enhancing the actions of bradykinin on B(2) receptors independent of blocking its inactivation. To investigate further the importance of ACE kininase activity on BK-induced vasodilation, we investigated the effect of inhibiting ACE, as well as other kininases, on both BK metabolism and vasodilator effect in preparations that exhibit increased ACE activity. Mesenteric arterial beds obtained from 1-kidney, 1-clip hypertensive rats presented augmented ACE and angiotensin I converting activities compared with normotensive rats. The isolated and perfused mesenteric beds were exposed to BK for 15 minutes in the absence or in the presence of kininase inhibitors; then, the perfusate was collected for analysis of the products of BK metabolism by high-performance liquid chromatography. BK was metabolized to the fragments BK(1-8), BK(1-7), and BK(1-5), and the recovery of intact BK was reduced by 47% in the hypertensive group. Recovery of BK was increased in both groups in the presence of a kininase I inhibitor and in the hypertensive group by neutral endopeptidase 24.11 inhibitor; however, ACE inhibition did not affect BK metabolism in both groups. In contrast, only the ACE inhibitor potentiated the vasodilator effect of BK in a mesenteric bed preconstricted with phenylephrine; the increase in BK effect, nevertheless, was not greater in arteries from hypertensive rats that presented an increased ACE activity when compared with those in the normotensive group. These data demonstrated that ACE inhibitor-induced potentiation of BK vasodilator effects is not related to their actions on BK degradation.
Collapse
Affiliation(s)
- Disney O Sivieri
- Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto-USP, Ribeirão Preto, São Paulo, Brazil
| | | | | | | | | |
Collapse
|
16
|
Becari C, Sivieri DO, Santos CF, Moysés MK, Oliveira EB, Salgado MCO. Role of Elastase-2 as an Angiotensin II-Forming Enzyme in Rat Carotid Artery. J Cardiovasc Pharmacol 2005; 46:498-504. [PMID: 16160604 DOI: 10.1097/01.fjc.0000177982.68563.98] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We have described the biochemical, enzymatic, and structural properties of a chymostatin-sensitive angiotensin (Ang) I-converting elastase-2 found in the rat mesenteric arterial bed perfusate. We determined the mRNA for elastase-2 and its relative role in generating Ang II in the rat isolated aorta and carotid artery rings. In carotid rings, the Ang I-induced vasoconstrictor effect was only partially inhibited by captopril or chymostatin, whereas that of tetradecapeptide renin substrate (TDP) was greatly inhibited by chymostatin but unaffected by captopril; however, Ang I- and TDP-induced effects were abolished by the combination of both inhibitors. Effects of [Pro11-D-Ala12]-Ang I (PDA), an Ang I-converting enzyme (ACE)-resistant biologically inactive precursor of Ang II were blocked by chymostatin or N-acetyl-Ala-Ala-Pro-Leu-chloromethylketone (elastase-2 inhibitor) in carotid artery. PDA failed to induce an effect in aortic rings, and Ang I-induced contractions were completely inhibited by captopril. The mRNA for rat elastase-2 was detected in aorta, carotid, and mesenteric arteries, although its expression was found to be less important in aorta. These findings indicate the presence of a functional alternative pathway to ACE for Ang II generation in rat carotid artery and represent strong evidence of a physiological role for elastase-2; however, its functional contribution to Ang II formation in aorta appears to be negligible.
Collapse
Affiliation(s)
- Christiane Becari
- Department of Pharmacology, University of São Paulo, School of Medicine of Ribeirão Preto, Ribeirão Preto, Brazil 14049-900
| | | | | | | | | | | |
Collapse
|
17
|
Santos CF, Greene AS, Salgado MCO, Oliveira EB. Conversion of renin substrate tetradecapeptide to angiotensin II by rat MAB elastase-2. Can J Physiol Pharmacol 2004; 82:1000-5. [PMID: 15644940 DOI: 10.1139/y04-102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A new approach for the purification of rat mesenteric arterial bed (MAB) elastase-2 has been developed using the chromogenic substrates N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide and N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide to monitor the enzymatic activity during various stages of purification. The purified enzyme was evaluated in the presence of various inhibitors and confirmed to have angiotensin (Ang) II-forming ability. The active site-directed inhibitor acetyl-Ala-Ala-Pro-Leu-chloromethylketone (100 µmol·L-1), described for human pancreatic elastase-2, abolished the enzymatic activity, confirming that the enzyme is an elastase-2. Chymostatin (100 µmol·L-1), an inhibitor regarded as selective for chymases, also showed a remarkable inhibitory effect (94%), whereas captopril (100 µmol·L-1) had no effect at all on the Ang II-forming activity. The Ang II precursor renin substrate tetradecapeptide (RS-14P) was converted into Ang II by the rat MAB elastase-2 with the following kinetic constants: Km= 124 ± 21 µmol·L-1; Kcat= 629 min-1; catalytic efficiency (Kcat/Km) = 5.1 min-1µ(mol/L)-1. In conclusion, the strategy for the purification of rat MAB elastase-2 with the chromogenic substrates proved to be simple, rapid, accurate, and highly reproducible; therefore, it can be reliably and conveniently used to routinely purify this enzyme. The kinetic parameters for the formation of Ang II from RS-14P by rat MAB elastase-2 emphasize differences in substrate specificity between this and other Ang II-forming enzymes.Key words: N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide, N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide, elastase-2, angiotensin II, renin substrate tetradecapeptide.
Collapse
Affiliation(s)
- Carlos F Santos
- Discipline of Pharmacology, Bauru School of Dentistry, University of São Paulo, Brazil
| | | | | | | |
Collapse
|
18
|
Santos CF, Caprio MAV, Oliveira EB, Salgado MCO, Schippers DN, Munzenmaier DH, Greene AS. Functional role, cellular source, and tissue distribution of rat elastase-2, an angiotensin II-forming enzyme. Am J Physiol Heart Circ Physiol 2003; 285:H775-83. [PMID: 12714330 DOI: 10.1152/ajpheart.00818.2002] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We recently described a chymostatin-sensitive elastase-2 as the major angiotensin (ANG) II-forming enzyme in the perfusate of the rat mesenteric arterial bed (MAB) with the same cDNA sequence as rat pancreatic elastase-2. The role of this enzyme in generating ANG II was examined in the rat isolated and perfused MAB. The vasoconstrictor effect elicited by ANG I and the renin substrate tetradecapeptide was only partially inhibited by captopril but abolished by the combination of captopril and chymostatin or N-acetyl-Ala-Ala-Pro-Leu-chloromethylketone (Ac-AAPL-CK; inhibitor originally developed for human elastase-2). The effect induced by [Pro11,d-Ala12]-ANG I, an ANG I-converting enzyme (ACE)-resistant biologically inactive precursor of ANG II, was blocked by chymostatin or Ac-AAPL-CK. It was also demonstrated that cultured rat mesenteric endothelial cells synthesize elastase-2 and that mRNA for this enzyme can be detected in different rat tissues such as the pancreas, MAB, lung, heart, kidney, liver, and spleen. In conclusion, the demonstration of a functional alternative pathway to ACE for ANG II generation in the rat MAB and the fact that cultured MAB endothelial cells are capable of producing and secreting elastase-2 represent strong evidence of a physiological role for this enzyme in the rat vasculature.
Collapse
Affiliation(s)
- Carlos F Santos
- Department of Pharmacology, University of São Paulo School of Medicine, Ribeirão Preto 14049-900, Brazil
| | | | | | | | | | | | | |
Collapse
|