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Mesquita LSF, Matos TS, Ávila FDN, Batista ADS, Moura AF, de Moraes MO, da Silva MCM, Ferreira TLA, Nascimento NRF, Monteiro NKV, Pessoa ODL. Diterpenoids from Leaves of Cultivated Plectranthus ornatus. Planta Med 2021; 87:124-135. [PMID: 32746472 DOI: 10.1055/a-1209-3252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Two new diterpenoid derivatives 7α,12β,17-triacetoxy-6β,19-dihydroxy-13β,16-spirocicloabiet-8-ene-11,14-dione ( 1: ) and 6β-acetoxy-3β,7α,12α-trihydroxy-13β,16-spirocicloabiet-8-ene-11,14-dione ( 2: ) along with 11 ( 3: - 13: ) miscellaneous compounds were isolated from the leaves of Plectranthus ornatus Codd. Their structures were elucidated by spectroscopic analysis and gauge independent atomic orbitals 13C NMR calculations. The isolated compounds were screened for their effects on intestinal motility using guinea-pig ileum and duodenum and by their cytotoxicity against 4 human cancer cell lines (HCT-116, SF-295, PC-3, and HL-60). Compounds 6: and 9: were moderately cytotoxic against HL-60, whereas 6: and 13: were more active on SF-295 and HCT-116.
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Affiliation(s)
| | - Taynara Simão Matos
- Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Fortaleza-CE, Brazil
| | | | - Alison da Silva Batista
- Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Fortaleza-CE, Brazil
| | - Andréa Felinto Moura
- Núcleo de Pesquisa e Desenvolvimento de Medicamentos, Universidade Federal do Ceará, Fortaleza-CE, Brazil
| | - Manoel Odorico de Moraes
- Núcleo de Pesquisa e Desenvolvimento de Medicamentos, Universidade Federal do Ceará, Fortaleza-CE, Brazil
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Sousa LGF, Cortez LUADS, Evangelista JSAM, Xavier-Júnior FAF, Heimark DB, Fonteles MC, Santos CF, Nascimento NRF. Renal protective effect of pinitol in experimental diabetes. Eur J Pharmacol 2020; 880:173130. [PMID: 32360975 DOI: 10.1016/j.ejphar.2020.173130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 04/17/2020] [Accepted: 04/20/2020] [Indexed: 01/17/2023]
Abstract
Pinitol is a natural antidiabetic agent shown to prevent or ameliorate metabolic and overall vascular and neural function. In the present study we have evaluated the potential benefits of pinitol on renal function of streptozotocin (STZ)-induced diabetic rats. Both euglycemic or 8-week or 16-week diabetic rats were treated with either saline (1 ml/kg/12h; p.o) or pinitol (20 mg/kg/12h; p.o). The renal function was evaluated by using metabolic cages, renal hemodynamic and tubular parameters measurements. Histological examination and evaluation of the protein expression of renal markers such as nephrin, TGFβ and pERK were also performed. Pinitol decreased by 50% the increased urinary albumin/creatinine ratio in both 8-week and 16 week diabetic rats. In addition, the glomerular volume of 16-week rats increased by 55% and this increase was blunted by pinitol. Remarkably, pressure-natriuresis was completely blunted in both 8 and 16-week diabetic rats but this impairment was prevented by pinitol in both treatment regimens. Pinitol ameliorated renal lesions and also prevented the decrease in nephrin expression and the increase of pERK and TGFβ expression in both diabetic groups. Natriuresis due to high renal perfusion pressure increased 7-fold in control animals but was blocked in 16-week diabetic rats and remarkably pinitol partially restored pressure natriuresis (3-fold increase in sodium excretion during pressure natriuresis). Pinitol prevents and ameliorates albuminuria, glomerular expansion, impairment of pressure-natriuresis, renal structural alterations and changes of renal markers and has the potential to be tested for the prevention of diabetic kidney disease.
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Affiliation(s)
- Luis Gustavo Farias Sousa
- Instituto Superior de Ciências Biomédicas, Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual do Ceará, Fortaleza, Brazil
| | - Lôrrainy Umbelina Alves de Souza Cortez
- Instituto Superior de Ciências Biomédicas, Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual do Ceará, Fortaleza, Brazil; Curso de Nutrição, Universidade de Fortaleza (UNIFOR), Brazil
| | - Janaína Serra Azul Monteiro Evangelista
- Instituto Superior de Ciências Biomédicas, Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual do Ceará, Fortaleza, Brazil; Programa de Pós-Graduação em Ciências Veterinárias, Universidade Estadual do Ceará, Brazil
| | | | - Douglas Biggam Heimark
- Instituto Superior de Ciências Biomédicas, Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual do Ceará, Fortaleza, Brazil
| | - Manassés Claudino Fonteles
- Instituto Superior de Ciências Biomédicas, Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual do Ceará, Fortaleza, Brazil
| | - Claudia Ferreira Santos
- Instituto Superior de Ciências Biomédicas, Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual do Ceará, Fortaleza, Brazil
| | - Nilberto Robson Falcão Nascimento
- Instituto Superior de Ciências Biomédicas, Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual do Ceará, Fortaleza, Brazil.
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Farias VX, Uchoa PN, Aquino CP, Britto LRG, Fonteles MC, Leal-Cardoso JH, Silva-Alves KS, Havt A, Prata MMG, Heimark DB, Nascimento NRF, Santos CF. Expression of myo-inositol cotransporters in the sciatic nerve and dorsal root ganglia in experimental diabetes. ACTA ACUST UNITED AC 2019; 52:e8589. [PMID: 31166385 PMCID: PMC6556969 DOI: 10.1590/1414-431x20198589] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 04/09/2019] [Indexed: 02/03/2023]
Abstract
The transport of myo-inositol is the main mechanism for the maintenance of its high intracellular levels. We aimed to measure the mRNA and protein levels of myo-inositol cotransporters in the sciatic nerve (SN) and dorsal root ganglia (DRG) during experimental diabetes. Streptozotocin-induced (STZ; 4, 8, and 12 weeks; 65 mg/kg; ip) diabetic rats (DB) and age-matched euglycemic (E) rats were used for the analysis of mRNA and protein levels of sodium myo-inositol cotransporters 1, 2 (SMIT1, SMIT2) or H+/myo-inositol cotransporter (HMIT). There was a significant reduction in the mRNA levels for SMIT1 in the SN and DRG (by 36.9 and 31.0%) in the 4-week DB (DB4) group compared to the E group. SMIT2 was not expressed in SN. The mRNA level for SMIT2 was up-regulated only in the DRG in the DB4 group. On the other hand, the protein level of SMIT1 decreased by 42.5, 41.3, and 44.8% in the SN after 4, 8, and 12 weeks of diabetes, respectively. In addition, there was a decrease of 64.3 and 58.0% of HMIT in membrane and cytosolic fractions, respectively, in the SN of the DB4 group. In the DRG, there was an increase of 230 and 86.3% for SMIT1 and HMIT, respectively, in the DB12 group. The levels of the main inositol transporters, SMIT1 and HMIT, were greatly reduced in the SN but not in the DRG. SMIT-1 was selectively reduced in the sciatic nerve during experimental STZ-induced diabetes.
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Affiliation(s)
- V X Farias
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - P N Uchoa
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - C P Aquino
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - L R G Britto
- Instituto de Ciências Biomédicas, Laboratório de Neurofisiologia, Universidade de São Paulo, SP, Brasil
| | - M C Fonteles
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - J H Leal-Cardoso
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - K S Silva-Alves
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - A Havt
- Instituto de Ciências Biomédicas, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - M M G Prata
- Instituto de Ciências Biomédicas, Universidade Federal do Ceará, Fortaleza, CE, Brasil
| | - D B Heimark
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - N R F Nascimento
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
| | - C F Santos
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brasil
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Lessa LMA, Godinho AN, Lopes MB, Mateus RG, Oliveira NO, Nascimento NRF, Santos CF, Fonteles MC. Modulation of NHE3 Activity in Rat Renal Proximal Tubules during the Estrous Cycle Phases and Direct Impact of Estradiol and Progesterone. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.862.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Renan Gois Mateus
- Superior Biomedical Sciences InstituteState University of CearaFortalezaBrazil
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Santos CF, Céron JDG, Bindá AH, Possani LD, Vidal JB, Fonteles MC, Nascimento NRF. Cardiovascular effects of the scorpions Centruroides margaritatus, Centruroides limpidus and Centruroides noxius crude venom. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.812.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Lourival D Possani
- Instituto de BiotecnologíaUniversidad Nacional Autónoma de MéxicoCuernavacaMexico
| | - José Béltran Vidal
- Grupo de Investigaciones Herpetológicas y ToxinológicasUniversidad del CaucaPopayánColombia
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Fonteles MC, Silva AG, Fonseca MJS, Santos CF, lopes DEL, Silva MCM, Nascimento NRF. Lipoic Acid Prevents Renal Dysfunction in Experimental Diabetes. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.678.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Ariana Gomes Silva
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do CearáFortalezaBrazil
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Nascimento NRF, Lopes LGF, Sousa EHS, Santos CF, Paz IA, Filho PMS, Longhinotti E, Fonteles MC. Sodium nitroprusside encapsulated in Silica nanoparticles as a strategy for safer nitric oxide delivery. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.679.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Linhares BL, Nascimento NRF, Gonzaga-Silva LF, Santos CF, Moraes MO, Marinho LB, Silva APG, Fonteles MC, Reges R. Effect of co-administration of two different phosphodiesterase inhibitors and a β3-adrenoceptor agonist in an experimental model of detrusor overactivity. Eur J Pharmacol 2018; 833:425-431. [DOI: 10.1016/j.ejphar.2018.06.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/13/2018] [Accepted: 06/15/2018] [Indexed: 02/07/2023]
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Leitão Junior AS, Campos RM, Cerqueira JBG, Fonteles MC, Santos CF, de Nucci G, Sousa EHS, Lopes LGF, Gonzaga-Silva LF, Nascimento NRF. Relaxant effect of a metal-based drug in human corpora cavernosa and its mechanism of action. Int J Impot Res 2015; 28:20-4. [PMID: 26510967 DOI: 10.1038/ijir.2015.27] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 07/10/2015] [Accepted: 09/22/2015] [Indexed: 11/09/2022]
Abstract
We studied the mechanisms involved in the human corpora cavernosa (HCC) relaxation induced by a new metal-based nitric oxide (NO) donor, the ruthenium complex cis-[Ru(bpy)2Imn(NO)](+3) (FOR0811). FOR0811 produced relaxation in phenylephrine (PE)-precontracted HCC with a maximal response that achieved 112.9 ± 10.6%. There was no difference between the maximal relaxation induced by FOR0811 when compared with sodium nitroprusside (SNP) (106.8 ± 7.3%), BAY41-2272 (107.6 ± 4.1%) or vardenafil (103.4 ± 3.8%), however, FOR0811 was less potent than SNP and vardenafil. L-N(G)-nitroarginine methyl ester (L-NAME), a NO synthase inhibitor, had no effect in the concentration-response curve elicited by FOR0811. 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a heme-site inhibitor of soluble guanylyl cyclase (sGC) was able to either block or reverse the relaxation induced by FOR0811. On the other hand, the relaxation induced by FOR0811 was not affected by glibenclamide, a blocker of ATP-sensitive potassium channels. FOR0811 (10 μM) was able to increase cyclic guanosine monophosphate (cGMP) levels in corpora cavernosa strips. FOR0811 completely relaxes HCC by a sGC-cGMP-dependent mechanism and can be a lead compound in the development of new stable NO donors.
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Affiliation(s)
- A S Leitão Junior
- Departamento de Cirurgia, Divisão de Urologia, Universidade Federal do Ceará, Fortaleza, Brazil
| | - R M Campos
- Physiology and Pharmacology, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil
| | - J B G Cerqueira
- Departamento de Cirurgia, Divisão de Urologia, Universidade Federal do Ceará, Fortaleza, Brazil
| | - M C Fonteles
- Departamento de Fisiologia e Farmacologia, Universidade Federal do Ceará, Fortaleza, Brazil
| | - C F Santos
- Physiology and Pharmacology, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil
| | - G de Nucci
- Faculdade de Ciências Médicas, Departamento de Farmacologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - E H S Sousa
- Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Fortaleza, Brazil
| | - L G F Lopes
- Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, Fortaleza, Brazil
| | - L F Gonzaga-Silva
- Departamento de Cirurgia, Divisão de Urologia, Universidade Federal do Ceará, Fortaleza, Brazil
| | - N R F Nascimento
- Physiology and Pharmacology, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, Brazil
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Teixeira MDA, Nascimento NRF, Fonteles MC, Vale OC. Uroguanylin induces electroencephalographic spikes in rats. BRAZ J BIOL 2013; 73:623-7. [PMID: 24212704 DOI: 10.1590/s1519-69842013000300021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 03/21/2013] [Indexed: 11/21/2022] Open
Abstract
Uroguanylin (UGN) is an endogenous peptide that acts on membrane-bound guanylate cyclase receptors of intestinal and renal cells increasing cGMP production and regulating electrolyte and water epithelial transport. Recent research works demonstrate the expression of this peptide and its receptor in the central nervous system. The current work was undertaken in order to evaluate modifications of electroencephalographic spectra (EEG) in anesthetized Wistar rats, submitted to intracisternal infusion of uroguanylin (0.0125 nmoles/min or 0.04 nmoles/min). The current observations demonstrate that 0.0125 nmoles/min and 0.04 nmoles/min intracisternal infusion of UGN significantly enhances amplitude and frequency of sharp waves and evoked spikes (p = 0.03). No statistical significance was observed on absolute alpha and theta spectra amplitude. The present data suggest that UGN acts on bioelectrogenesis of cortical cells by inducing hypersynchronic firing of neurons. This effect is blocked by nedocromil, suggesting that UGN acts by increasing the activity of chloride channels.
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Affiliation(s)
- M D A Teixeira
- Pharmacology and Physiology Department, Biomedicine Institute, Clinical Research Unit, Federal University of Ceará, FortalezaCE, Brazil
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Fonteles MC, Sousa‐Filho JE, Nascimento NRF, Araujo‐Filho RM. The effect of glutamine and alanylglutamine as substrates for the isolated perfused rabbit kidney. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.889.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Nascimento NRF, Campos RM, Costa PPC, Fonteles MC, Santos CF, Sá DS, Sousa EH, França LGL. Metal‐Based Guanylate Cyclase Stimulators/Activators. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1115.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Manassés C Fonteles
- Superior Institute of Biomedical SciencesCeará State UniversityFortalezaBrazil
| | - Cláudia F Santos
- Superior Institute of Biomedical SciencesCeará State UniversityFortalezaBrazil
| | | | - Eduardo H Sousa
- Inorganic ChemistryFederal University of CearáFortalezaBrazil
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Gomes VM, Pessoa ODL, Fonteles MC, Santos CF, Sudo RT, Nascimento NRF. Physalin promotes positive cardiac inotropism by a PKARYR2‐ dependent pathway. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1117.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Roberto Takashi Sudo
- Basic and Clinical PharmacologyFederal University of Rio de JaneiroRio de JaneiroBrazil
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Fonteles MC, Teixeira MDA, Nascimento NRF, Vale OC. Uroguanylin Promotes Eletroencephalographic Changes in Rat Brain. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.843.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Salles HO, Vasconcelos IM, Santos LFL, Oliveira HD, Costa PPC, Nascimento NRF, Santos CF, Sousa DF, Jorge ARC, Menezes DB, Monteiro HSA, Gondim DMF, Oliveira JTA. Towards a better understanding of Ipomoea asarifolia toxicity: evidence of the involvement of a leaf lectin. Toxicon 2011; 58:502-8. [PMID: 21878348 DOI: 10.1016/j.toxicon.2011.08.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 07/22/2011] [Accepted: 08/18/2011] [Indexed: 11/30/2022]
Abstract
Natural intoxication of livestock by ingestion of Ipomoea asarifolia leaves has been reported to occur widely in Brazil. Previous studies carried out by our research group provided strong evidence that a lectin could be involved with the toxic properties of I. asarifolia. To reinforce this hypothesis, a lectin-enriched fraction (LEF) was isolated from I. asarifolia leaves and its toxic effects were assessed. Leaves of I. asarifolia were excised from plants growing widely in the field, mechanically wounded and maintained in a chamber at 25 ± 3 °C for 72h in the dark, under near 100% relative humidity. The leaf proteins were extracted, ammonium sulfate precipitated, chromatographed on DEAE-cellulose and Phenyl-Sepharose to produce LEF that under SDS-PAGE showed a molecular mass of 44.0 kDa and after N-terminal amino acid analysis a primary sequence composed of AGYTPVLDIGAEVLAAGEPY. The in vivo toxicity of LEF assessed by intraorbital injection in mice showed induced severe uncoordinated movements without death. LEF reduced the muscular contraction in a dose depend way and at 29.8 μg/mL (CE(50)) it produces 50% inhibition of contraction, suggesting that LEF blunts autonomic neurotransmission. Isolated rat kidneys were perfused with LEF and no effects on the perfusion pressure or renal vascular resistance were observed, but urinary flow and glomerular filtration rate increased. Moreover, the percentage of tubular transport of Na(+), K(+) and Cl(-) decreased. Histological examination of the kidneys perfused with LEF exhibited little alterations. These toxic effects observed above were concomitant with the increase of LEF hemagglutination activity, which strongly suggest that one of the toxic principles of I. asarifolia is a lectin present in its leaves.
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Affiliation(s)
- H O Salles
- Embrapa Caprinos e Ovinos, PO Box 145, 62010-970, Sobral, CE, Brazil
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Farias VX, Macêdo FHP, Oquendo MB, Tomé AR, Báo SN, Cintra DOS, Santos CF, Albuquerque AAC, Heimark DB, Larner J, Fonteles MC, Leal-Cardoso JH, Nascimento NRF. Chronic treatment with D-chiro-inositol prevents autonomic and somatic neuropathy in STZ-induced diabetic mice. Diabetes Obes Metab 2011; 13:243-50. [PMID: 21205116 DOI: 10.1111/j.1463-1326.2010.01344.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM D-chiro-inositol (DCI) has been shown to prevent and reverse endothelial dysfunction in diabetic rats and rabbits. The present study evaluates the preventive effect of DCI on experimental diabetic neuropathy (DN). METHODS Streptozotocin-induced (STZ) diabetic mice were treated by oral gavage for 60 days with DCI (20 mg/kg/12 h) or saline (NaCl 0.9%; 0.1 ml/10 g/12 h; Diab) and compared with euglycaemic groups treated with saline (0.1 ml/10 g/12 h; Eugly). We compared the response of the isolated sciatic nerve, corpora cavernosa or vas deferens to electrical stimulation. RESULTS The electrically evoked compound action potential of the sciatic nerve was greatly blunted by diabetes. The peak-to-peak amplitude (PPA) was decreased from 3.24 ± 0.7 to 0.9 ± 0.2 mV (p < 0.05), the conduction velocity (CV) of the first component was reduced from 46.78 ± 4.5 to 26.69 ± 3.8 ms (p < 0.05) and chronaxy was increased from 60.43 ± 1.9 to 69.67 ± 1.4 ms (p < 0.05). These parameters were improved in nerves from DCI-treated mice (p < 0.05). PPA in the DCI group was 5.79 ± 0.8 mV (vs. 0.9 ± 0.2 mV-Diab; p < 0.05) and CV was 45.91 ± 3.6 ms (vs. 26.69 ± 3.8 ms-Diab; p < 0.05). Maximal relaxation of the corpus cavernosum evoked by electrical stimulation (2-64 Hz) in the Diab group was 36.4 ± 3.8% compared to 65.4 ± 2.8% in Eugly and 59.3 ± 5.5% in the DCI group (p < 0.05). Maximal contraction obtained in the vas deferens was 38.0 ± 9.2% in Eugly and 11.5 ± 2.6% in Diab (decrease of 69.7%; p < 0.05), compared to 25.2 ± 2.3% in the DCI group (p < 0.05 vs. diabetic). Electron microscopy of the sciatic nerves showed prevention of neuronal damage. CONCLUSIONS DCI has a neuroprotective action in both autonomic and somatic nerves in STZ-induced DN.
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Affiliation(s)
- V X Farias
- Department of Physiology and Pharmacology, Superior Institute of Biomedical Sciences, Fortaleza, Ceará, Brazil
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Nascimento NRF, Refosco RMDC, Vasconcelos ECF, Kerntopf MR, Santos CF, Batista FJA, De Sousa CM, Fonteles MC. 1,8-Cineole induces relaxation in rat and guinea-pig airway smooth muscle. J Pharm Pharmacol 2010. [DOI: 10.1211/jpp.61.03.0011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Nascimento NRF, Refosco RMDC, Vasconcelos ECF, Kerntopf MR, Santos CF, Batista FJA, De Sousa CM, Fonteles MC. 1,8-Cineole induces relaxation in rat and guinea-pig airway smooth muscle. J Pharm Pharmacol 2009; 61:361-6. [PMID: 19222909 DOI: 10.1211/jpp/61.03.0011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES 1,8-Cineole is a monoterpene with anti-inflammatory, vascular and intestinal smooth muscle relaxant activity. We have evaluated the potential bronchodilatatory activity of this compound. METHODS 1,8-Cineole was tested against carbachol, histamine, K+ 80 mM and ovalbumin-induced bronchial contractions in Wistar rat or guinea-pig tissues. Some of the guinea-pigs had been previously sensitized with an intramuscular injection of 5% (w/v) ovalbumin/saline solution. Control animals received 0.3 ml saline. In separate experimental groups the response to 1,8-cineole (1-30 mg/kg), phenoterol (0.05-5 mg/kg) or vehicle (0.3% Tween in saline) was studied. KEY FINDINGS 1,8-Cineole decreased, in vivo, rat bronchial resistance with similar efficacy as phenoterol (66.7 +/- 3.2% vs 72.1 +/- 5.3%). On the other hand, the maximal relaxant response to 1,8-cineole in carbachol-precontracted rat tracheas was 85.5 +/- 5.7% (IC50 = 408.9 (328-5196) microg/ml) compared with 80.2 +/- 4.8% (IC50 = 5.1 (4.3-6.1) microg/ml) with phenoterol. The addition of 1,8-cineole to guinea-pig tracheal rings tonically contracted with K+ 80 mM induced a concentration-related relaxation. The maximal relaxation elicited by 1,8-cineole was 113.6 +/- 11.7% (IC50 127.0 (115.9-139.2) microg/ml) compared with 129.7 +/- 14.6% (IC50 0.13 (0.12-0.14) microg/ml) achieved after phenoterol administration. In addition, the incubation of tracheal rings with 1,8-cineole (100, 300 or 1000 microg/ml), 15 min before inducing phasic contractions with K+ 80 mM, decreased the maximal amplitude of the contraction by 31.6 +/- 4.6, 75.7 +/- 2.7 and 92.2 +/- 1.5%, respectively. In another set of experiments, neither the maximal response nor the IC50 for the 1,8-cineole-induced relaxation were different between normal and ovalbumin-sensitized tissues. Moreover, the relaxation of bronchial rings contracted after exposure to 1 microg/ml ovalbumin occurred at a faster rate in rings pre-incubated with 1,8-cineole when compared with rings pre-incubated with vehicle only (Tween 0.3%). Therefore, in the first minute after the antigen challenge, the tracheal tissue relaxed after the peak contraction by 6.5, 21.4 (P < 0.05 vs control) and 66.9% (P < 0.05 vs control) in the presence of 100, 300 or 1000 microg/ml 1,8-cineole, respectively. CONCLUSIONS 1,8-Cineole relaxed rat and guinea-pig (nonsensitized and ovalbumin-sensitized) airway smooth muscle by a nonspecific mechanism.
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Carvalho AF, Santos-Neto MS, Monteiro HSA, Freitas SM, Morhy L, Nascimento NRF, Fonteles MC. BTCI enhances guanylin-induced natriuresis and promotes renal glomerular and tubular effects. BRAZ J BIOL 2008; 68:149-54. [PMID: 18470390 DOI: 10.1590/s1519-69842008000100021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Accepted: 07/19/2006] [Indexed: 11/22/2022] Open
Abstract
Guanylin and uroguanylin are small cysteine-rich peptides involved in the regulation of fluid and electrolyte homeostasis through binding and activation of guanylyl cyclases signaling molecules expressed in intestine and kidney. Guanylin is less potent than uroguanylin as a natriuretic agent and is degraded in vitro by chymotrypsin due to unique structural features in the bioactive moiety of the peptide. Thus, the aim of this study was to verify whether or not guanylin is degraded by chymotrypsin-like proteases present in the kidney brush-border membranes. The isolated perfused rat kidney assay was used in this regard. Guanylin (0.2 microM) induced no changes in kidney function. However, when pretreated by the black-eyed pea trypsin and chymotrypsin inhibitor (BTCI - 1.0 microM; guanylin - 0.2 microM) it promoted increases in urine flow (DeltaUF of 0.25 +/- 0.09 mL.g(-1)/min, P < 0.05) and Na+ excretion (% Delta ENa+ of 18.20 +/- 2.17, P < 0.05). BTCI (1.0 microM) also increased %ENa+ (from 22.8 +/- 1.30 to 34.4 +/- 3.48, P < 0.05, 90 minutes). Furthermore, BTCI (3.0 microM) induced increases in glomerular filtration rate (GFR; from 0.96 +/- 0.02 to 1.28 0.02 mL.g(-1)/min, P < 0.05, 60 minutes). The present paper strongly suggests that chymotrypsin-like proteases play a role in renal metabolism of guanylin and describes for the first time renal effects induced by a member of the Bowman-Birk family of protease inhibitors.
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Affiliation(s)
- A F Carvalho
- Instituto de Biomedicina, Universidade Federal do Ceará, Fortaleza, Ceará, Brazil
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Fonteles MC, Cerqueira JBG, Sousa CM, Alencar Cunha KM, Lopes LGF, Sousa Moreira Ì, Nascimento NRF. Potent endonthelial‐independent relaxation promoted by a nitrosyl ruthenium complex in rabbit aorta and corpora cavernosa. FASEB J 2008. [DOI: 10.1096/fasebj.22.1_supplement.916.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Campos AR, Cunha KMA, Santos FA, Silveira ER, Uchoa DEA, Nascimento NRF, Rao VSN. Relaxant effects of an alkaloid-rich fraction from Aspidosperma ulei root bark on isolated rabbit corpus cavernosum. Int J Impot Res 2007; 20:255-63. [PMID: 18046335 DOI: 10.1038/sj.ijir.3901624] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We described earlier that an alkaloid-rich fraction (F(3-5)) from Aspidosperma ulei (Markgr) induces penile erection-like behavioral responses in mice. This study verified a possible relaxant effect of this fraction on isolated rabbit corpus cavernosum (RbCC) strips precontracted by phenylephrine (1 microM) or K+ 60 mM. F(3-5) (1-300 microg ml(-1)) relaxed the RbCC strips in a concentration-dependent and reversible manner. The relaxant effect of F(3-5) (100 microg ml(-1)) on phenylephrine contraction was unaffected in the presence of atropine, N-omega-nitro-L-arginine methyl ester or 1H-[1,2,4]oxadiazole[4,3-a] quinoxalin-1-one and by preincubation with tetrodotoxin, glibenclamide, apamine and charybdotoxin suggesting that mechanisms other than cholinergic, nitrergic, sGC activation or potassium channel opening are probably involved. However, the phasic component of the contraction induced by K+ 60 mM as well as the maximal contraction elicited by increasing external Ca2+ concentrations in depolarized corpora cavernosa was inhibited by F(3-5). We conclude that F(3-5) relaxes the RbCC smooth muscle, at least in part, through a blockade of calcium influx or its function.
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Affiliation(s)
- A R Campos
- Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, CE, Brazil
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Fonteles MC, Sousa CM, Cerqueira JBG, Batista FJA, Santos CF, Silva LFG, Nascimento NRF. Uroguanylin Relaxes Human Corpus Cavernosum and is Potentiated by Vardenafil. FASEB J 2007. [DOI: 10.1096/fasebj.21.5.a433-a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Clauber Mota Sousa
- Superior Institute of BiomedicineUECE, Av. Paranjana, 1700, ItaperiFortaleza60740 000Brazil
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Fontenelle ROS, Morais SM, Brito EHS, Kerntopf MR, Brilhante RSN, Cordeiro RA, Tomé AR, Queiroz MGR, Nascimento NRF, Sidrim JJC, Rocha MFG. Chemical composition, toxicological aspects and antifungal activity of essential oil from Lippia sidoides Cham. J Antimicrob Chemother 2007; 59:934-40. [PMID: 17376793 DOI: 10.1093/jac/dkm066] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The aims of this study were to test the essential oil from Lippia sidoides Cham. for antifungal activity, in vitro, against Candida spp. and Microsporum canis, to evaluate its acute and subchronic toxicological effects, in vivo, and to determine its chemical constituents. METHODS The antifungal activity, in vitro, was initially evaluated by the agar-well diffusion technique, and the MIC and minimum fungicidal concentration (MFC) were determined by the broth microdilution method. The acute and subchronic toxicological effects were determined in mice and rats, respectively. The chemical composition of the essential oil was determined by gas chromatography coupled to mass spectroscopy. RESULTS The essential oil obtained from L. sidoides was effective against all tested strains by the agar-well diffusion method. The MICs of L. sidoides essential oil for strains of M. canis ranged from 4 to 70 mg/L and the MFCs ranged from 9 to 150 mg/L. The MICs for strains of Candida spp. ranged from 620 to 2500 mg/L and the MFCs ranged from 1250 to 5000 mg/L. The main constituents of L. sidoides essential oil were thymol (59.65%), E-caryophyllene (10.60%) and p-cymene (9.08%). The acute administration of the essential oil up to 3 g/kg by the oral route to mice was devoid of overt toxicity. The 30 day oral administration of L. sidoides oil (117.95 mg/kg/day) to rats did not induce any significant histopathological, haematological or serum biochemical alterations. CONCLUSIONS The essential oil from L. sidoides may be a promising source in the search for new antifungal drugs due to its efficacy and low toxicity.
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Affiliation(s)
- R O S Fontenelle
- Post-Graduation Program in Veterinary Sciences, Veterinary Faculty, State University of Ceará, Fortaleza, Ceará, Brazil
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Barbosa PSF, Martins AMC, Alves RS, Amora DN, Martins RD, Toyama MH, Havt A, Nascimento NRF, Rocha VLC, Menezes DB, Fonteles MC, Monteiro HSA. The role of indomethacin and tezosentan on renal effects induced by Bothrops moojeni Lys49 myotoxin I. Toxicon 2006; 47:831-7. [PMID: 16730045 DOI: 10.1016/j.toxicon.2006.01.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 01/12/2006] [Accepted: 01/16/2006] [Indexed: 11/25/2022]
Abstract
Renal changes determined by Lys49 myotoxin I (BmTx I), isolated from Bothrops moojeni are well known. The scope of the present study was to investigate the possible mechanisms involved in the production of these effects by using indomethacin (10 microg/mL), a non-selective inhibitor of cyclooxygenase, and tezosentan (10 microg/mL), an endothelin antagonist. By means of the method of mesenteric vascular bed, it has been observed that B. moojeni myotoxin (5 microg/mL) affects neither basal perfusion pressure nor phenylephrine-preconstricted vessels. This fact suggests that the increase in renal perfusion pressure and in renal vascular resistance did not occur by a direct effect on renal vasculature. Isolated kidneys from Wistar rats, weighing 240-280 g, were perfused with Krebs-Henseleit solution. The infusion of BmTx-I increased perfusion pressure, renal vascular resistance, urinary flow and glomerular filtration rate. Sodium, potassium and chloride tubular transport was reduced after addition of BmTx-I. Indomethacin blocked the effects induced by BmTx-I on perfusion pressure and renal vascular resistance, however, it did not revert the effect on urinary flow and sodium, potassium and chloride tubular transport. The alterations of glomerular filtration rate were inhibited only at 90 min of perfusion. The partial blockade exerted by indomethacin treatment showed that prostaglandins could have been important mediators of BmTx-I renal effects, but the participation of other substances cannot be excluded. The blockage of all renal alterations observed after tezosentan treatment support the hypothesis that endothelin is the major substance involved in the renal pathophysiologic alterations promoted by the Lys49 PLA(2) myotoxin I, isolated from B. moojeni. In conclusion, the rather intense renal effects promoted by B. moojeni myotoxin-I were probably caused by the release of renal endothelin, interfering with the renal parameters studied.
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Affiliation(s)
- P S F Barbosa
- Department of Physiology and Pharmacology, Federal University of Ceara, Fortaleza, Ceara, Brazil
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Nascimento NRF, Lessa LMA, Kerntopf MR, Sousa CM, Alves RS, Queiroz MGR, Price J, Heimark DB, Larner J, Du X, Brownlee M, Gow A, Davis C, Fonteles MC. Inositols prevent and reverse endothelial dysfunction in diabetic rat and rabbit vasculature metabolically and by scavenging superoxide. Proc Natl Acad Sci U S A 2006; 103:218-23. [PMID: 16373499 PMCID: PMC1325005 DOI: 10.1073/pnas.0509779103] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Indexed: 11/18/2022] Open
Abstract
Endothelial dysfunction (ED) is an early feature of cardiovascular risk and diabetes. Hyperglycemia and hyperlipidemia are causative factors. Excessive endothelial mitochondrial superoxide (ROS) production with hyperglycemia and hyperlipidemia is a key mechanism. Inositol components of an insulin inositol glycan mediator, d-chiro-inositol (DCI) and 3-O-methyl DCI (pinitol), decrease hyperglycemia and hyperlipidemia. We tested whether these, myoinositol and dibutyryl DCI (db-DCI), would prevent or reverse ED in diabetic rats and rabbits. Oral inositols reduced hyperglycemia and hypertriglyceridemia with different potencies and prevented ED in rat aortic rings and mesenteric beds. Inositols added in vitro to five diabetic tissues reversed ED. Relaxation by Ach, NO, and electrical field stimulation was potentiated by inositols in vitro in rabbit penile corpus cavernosa. Inositols in vitro restored impaired contraction by the eNOS inhibitor l-NAME and increased NO effectiveness. DCI and db-DCI decreased elevated ROS in endothelial cells in high glucose and db-DCI reduced PKC activation, hexosamine pathway activity, and advanced glycation end products to basal levels. Xanthine/xanthine oxidase generated superoxide was reduced by superoxide dismutase or inositols, with db-DCI efficacious in a mechanism requiring chelated Fe(3+). Histochemical examination of rat aortic rings for protein SNO demonstrated a decrease in diabetic rings with restoration by inositols. In summary, inositols prevented and reversed ED in rat and rabbit vessels, reduced elevated ROS in endothelial cells, potentiated nitrergic or vasculo-myogenic relaxations, and preserved NO signaling. These effects are related to their metabolic actions, direct superoxide scavenging, and enhancing and protecting NO signaling. Of the inositols tested, db-DCI was most effective.
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Affiliation(s)
- N R F Nascimento
- College of Veterinary Medicine, State University of Ceará, Fortaleza, 60455-970 Ceará, Brazil
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Silva LFG, Nascimento NRF, Fonteles MC, de Nucci G, Moraes ME, Vasconcelos PRL, Moraes MO. Phentolamine relaxes human corpus cavernosum by a nonadrenergic mechanism activating ATP-sensitive K+ channel. Int J Impot Res 2005; 17:27-32. [PMID: 15510188 DOI: 10.1038/sj.ijir.3901269] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To investigate the pharmacodynamics of phentolamine in human corpus cavernosum (HCC) with special attention to the role of the K+ channels. Strips of HCC precontracted with nonadrenergic stimuli and kept in isometric organ bath immersed in a modified Krebs-Henseleit solution enriched with guanethidine and indomethacine were used in order to study the mechanism of the phentolamine-induced relaxation. Phentolamine caused relaxation (approximately 50%) in HCC strips precontracted with K+ 40 mM. This effect was not blocked by tetrodotoxin (1 microM) (54.6+/-4.6 vs 48.9+/-6.4%) or (atropine (10 microM) (52.7+/-6.5 vs 58.6+/-5.6%). However, this relaxation was significantly attenuated by L-NAME (100 microM) (59.7+/-5.8 vs 27.8+/-7.1%; P<0.05; n = 8) and ODQ (100 microM) (62.7+/-5.1 vs 26.8+/-3.9%; P<0.05; n = 8). Charybdotoxin and apamin (K(Ca)-channel blockers) did not affect the phentolamine relaxations (54.6+/-4.6 vs 59.3+/-5.2%). Glibenclamide (100 microM), an inhibitor of K(ATP)-channel, caused a significant inhibition (56.7+/-6.3 vs 11.3+/-2.3%; P<0.05; n = 8) of the phentolamine-induced relaxation. In addition, the association of glibenclamide and L-NAME almost abolished the phentolamine-mediated relaxation (54.6+/-5.6 vs 5.7+/-1.4%; P<0.05; n = 8). The results suggest that phentolamine relaxes HCC by a nonadrenergic-noncholinergic mechanism dependent on nitric oxide synthase activity and activation of K(ATP)-channel.
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Affiliation(s)
- L F G Silva
- Surgery Department, Federal University of Ceara, Fortaleza, Ceara, Brazil.
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Camurça-Vasconcelos ALF, Nascimento NRF, Sousa CM, Melo LM, Morais SM, Bevilaqua CML, Rocha MFG. Neuromuscular effects and acute toxicity of an ethyl acetate extract of Spigelia anthelmia Linn. J Ethnopharmacol 2004; 92:257-261. [PMID: 15138009 DOI: 10.1016/j.jep.2004.03.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2002] [Accepted: 03/03/2004] [Indexed: 05/24/2023]
Abstract
An ethyl acetate extract of Spigelia anthelmia (EASa), with validated anthelmintic activity, was evaluated for its acute toxicity and general effects in albino Swiss mice and for neuromuscular relaxant activity in the frog sciatic-gastrocnemius and rectus abdominis preparation. The extract induced a dose-related myotonia and muscular paralysis of rapid onset at higher doses. The calculated LD50 after oral and intraperitoneal administration was 345.9 [241.4-484.7] mg/kg and 60.8 [47.4-80] mg/kg, respectively. In broilers, intramuscular injection of EASa-induced spastic paralysis qualitatively similar to that obtained after succinylcholine administration and contrasting to the flaccid paralysis induced by D-tubocurarine. The contraction elicited by direct stimulation of the gastrocnemius was blocked by EASa by 54.3+/-4.7% (IC50 = 21.4 [11.2-35.8] microg/ml) and the twitches evoked by stimulation of the sciatic nerve were blocked by 69.1+/-7.4% (IC50 = 17.9 [4.5-34.23] microg/ml). EASa also blocked acetylcholine-induced contractions in the frog rectus abdominis by 58.6+/-7.4% (IC50 = 7.4 [1.7-15.28] microg/ml) but did not decrease tonic contractions induced by a high-potassium Ringer solution. In summary, the ethyl acetate extract of Spigelia anthelmia induces tonic paralysis in vivo, and decreases amplitudes of twitches and increases tonus of skeletal muscle in vitro.
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Nascimento NRF, Costa-e-Forti A, Peter AA, Fonteles MC. Free radical scavengers improve the impaired endothelium-dependent responses in aorta and kidneys of diabetic rabbits. Diabetes Res Clin Pract 2003; 61:145-53. [PMID: 12965103 DOI: 10.1016/s0168-8227(03)00128-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The effects of two endogenous antioxidants, alpha-lipoic acid and reduced gluthathione (GSH), were evaluated in the response of the renal vasculature and aortic rings ex vivo of 4-week alloxan-diabetic rabbits to the endothelium-dependent agonists bradykinin (BK) and acetylcholine (Ach) or to the endothelium-independent agonist sodium nitroprusside (SNP) and compared with age and sex-matched euglycemic rabbits. The maximal decrease in perfusion pressure (R(max)) after BK infusion in the renal vasculature from diabetic rabbits was 5.4+/-1.3% (PD(2) 8 [12.6-3.4]) compared with 34.2+/-4.2% (PD(2) 9 [11.3-6.7]) (P<0.05) attained in tissues obtained from euglycemic rabbits. The addition of 1 microM lipoic acid or GSH improved (P<0.05) the R(max) to BK to 18.3+/-2.4% (PD(2) 8.6 [12.4-4.8]) and 19.5+/-3.7% (PD(2) 9.1 [13.3-4.9]), respectively. Similarly, the maximal vasorelaxant response to Ach in kidneys from diabetic rabbits was 16+/-2.0% (PD(2) 7.3 [10.4-4.2] whilst the R(max) in kidneys from euglycemic animals was 52.7+/-4.9% (PD(2) 11.3 [16.4-6.2]). Incubation with 1 microM alpha-lipoic acid or GSH restored the R(max) to Ach to 31+/-3.9% (PD(2) 9.8 [14.3-5.3]) and to 23+/-5.4% (PD(2) 7.6 [11.4-3.8], respectively. The vasodilatory response to SNP was unaltered among tissues from diabetic and euglycemic rabbits and was also unaffected by the treatments utilized. In addition, the R(max) to Ach in aortic rings of diabetic rabbits was 28.7+/-2.4% (PD(2) 8.3 [11.7-4.9]) compared with 100% (PD(2) 7.9 [12.1-3.7]) obtained in tissues gathered from euglycemic rabbits. The pretreatment of the tissues with alpha-lipoic acid restores the R(max) to 47.4+/-4% (PD(2) 11.1 [14.3-7.9]) and the pretreatment with GSH to 52+/-3.2% (PD(2) 9.8 [12.7-6.9]). Similarly, the response to SNP was unaltered in all groups. Lipoic acid and reduced gluthatione directly improved the endothelium-dependent response of renal arterioles and aortic rings of diabetic rabbits.
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Affiliation(s)
- N R F Nascimento
- College of Veterinary Medicine, State University of Ceara, PO box 3329, Zip Code 60436-160 Fortaleza, Ceará, Brazil
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