Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 421
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Pharmacol Sci ; 136(1): 26-30, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29277372

RESUMO

Chlorogenic acid (CGA) is a polyphenol found in coffee and medicinal herbs such as Lonicera japonica. In this study, the effect of CGA-induced relaxation on carbachol (CCh)-induced contraction of mouse urinary bladder was investigated. CGA (30-300 µg/ml) inhibited CCh- or U46619-induced contraction in a concentration-dependent manner. SQ22536 (adenylyl cyclase inhibitor) recovered CGA-induced relaxation of CCh-induced contraction; however, ODQ (guanylyl cyclase inhibitor) did not have the same effect. In addition, 3-isobutyl-1-methylxanthine (IBMX) enhanced CGA-induced relaxation; however, forskolin or sodium nitroprusside did not have the same effect. Moreover, Ro 20-1724, a selective phosphodiesterase (PDE) 4 inhibitor, enhanced CGA-induced relaxation, but vardenafil, a selective PDE5 inhibitor, did not have the same effect. In the presence of CCh, CGA increased cyclic adenosine monophosphate (cAMP) level, whereas SQ22536 inhibited the increase of cAMP levels. Moreover, higher cAMP levels were obtained with CGA plus IBMX treatment than the total cAMP levels obtained with separate CGA and IBMX treatments. In conclusion, these results suggest that CGA inhibited CCh-induced contraction of mouse urinary bladder by partly increasing cAMP levels via adenylyl cyclase activation.


Assuntos
Carbacol/antagonistas & inibidores , Ácido Clorogênico/farmacologia , Contração Muscular/efeitos dos fármacos , Relaxamento Muscular/efeitos dos fármacos , Bexiga Urinária/efeitos dos fármacos , 1-Metil-3-Isobutilxantina/farmacologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Adenilil Ciclases/metabolismo , Animais , Carbacol/farmacologia , AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Técnicas In Vitro , Masculino , Camundongos Endogâmicos , Inibidores da Fosfodiesterase 4/farmacologia
2.
Neuropharmacology ; 101: 271-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26449868

RESUMO

The cAMP signaling pathway has emerged as an important modulator of the pharmacological effects of ethanol. In this respect, the cAMP-dependent protein kinase has been shown to play an important role in the modulation of several ethanol-induced behavioral actions. Cellular levels of cAMP are maintained by the activity of adenylyl cyclases and phosphodiesterases. In the present work we have focused on ascertaining the role of PDE4 in mediating the neurobehavioral effects of ethanol. For this purpose, we have used the selective PDE4 inhibitor Ro 20-1724. This compound has been proven to enhance cellular cAMP response by PDE4 blockade and can be administered systemically. Swiss mice were injected intraperitoneally (i.p.) with Ro 20-1724 (0-5 mg/kg; i.p.) at different time intervals before ethanol (0-4 g/kg; i.p.) administration. Immediately after the ethanol injection, locomotor activity, loss of righting reflex, PKA footprint and enzymatic activity were assessed. Pretreatment with Ro 20-1724 increased ethanol-induced locomotor stimulation in a dose-dependent manner. Doses that increased locomotor stimulation did not modify basal locomotion or the suppression of motor activity produced by high doses of this alcohol. Ro 20-1724 did not alter the locomotor activation produced by amphetamine or cocaine. The time of loss of righting reflex evoked by ethanol was increased after pretreatment with Ro 20-1724. This effect was selective for the narcotic effects of ethanol since Ro 20-1724 did not affect pentobarbital-induced narcotic effects. Moreover, Ro 20-1724 administration increased the PKA footprint and enzymatic activity response elicited by ethanol. These data provide further evidence of the key role of the cAMP signaling pathway in the central effects of ethanol.


Assuntos
Depressores do Sistema Nervoso Central/toxicidade , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Etanol/toxicidade , Atividade Motora/efeitos dos fármacos , Estupor/induzido quimicamente , Estupor/enzimologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Depressores do Sistema Nervoso Central/sangue , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Etanol/sangue , Camundongos , Inibidores de Fosfodiesterase/farmacologia , Estatísticas não Paramétricas , Estupor/tratamento farmacológico , Fatores de Tempo
3.
Arterioscler Thromb Vasc Biol ; 34(8): 1689-96, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24925970

RESUMO

OBJECTIVE: Platelet-neutrophil interactions play a key role in cardiovascular disease and inflammatory processes. Src family kinases mediate P-selectin glycoprotein ligand-1-Mac-1 cross talk necessary for firm platelet-neutrophil adhesion. Because Src family kinase activity can be regulated by cAMP-dependent pathways, in this work, we evaluated the role of phosphodiesterases in the signaling events that are required to sustain platelet-neutrophil interactions and neutrophil recruitment at the site of vascular injury. APPROACH AND RESULTS: In neutrophils exposed to P-selectin, selective phosphodiesterase 4 (PDE4) inhibition prevented Src family kinase-mediated phosphorylation of the proline-rich tyrosine kinase 2 on Tyr579/Tyr580. The effects of PDE4 inhibition required protein kinase A, likely through protein kinase A-mediated activation of COOH-terminal Src kinase, a major negative regulator of Src family kinases. PDE4, but not other phosphodiesterase inhibitors, reduced platelet-neutrophil conjugates as well as neutrophil firm adhesion on spread platelets under flow conditions. The effect of PDE4 inhibition on neutrophil adhesion was primarily mediated by downregulation of P-selectin-induced activation of Mac-1. In a murine model of endovascular injury, selective inhibition of PDE4 significantly reduced neutrophil recruitment at the site of vascular damage. CONCLUSIONS: This study identifies PDE4 as a central node in the signaling network that mediates platelet-neutrophil adhesion and suggests that pharmacological inhibition of PDE4 may represent a novel therapeutic avenue for the treatment of cardiovascular disease.


Assuntos
Plaquetas/efeitos dos fármacos , Artéria Femoral/efeitos dos fármacos , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Selectina-P/metabolismo , Inibidores da Fosfodiesterase 4/farmacologia , Adesividade Plaquetária/efeitos dos fármacos , Lesões do Sistema Vascular/tratamento farmacológico , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Animais , Plaquetas/enzimologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Modelos Animais de Doenças , Artéria Femoral/enzimologia , Artéria Femoral/lesões , Quinase 2 de Adesão Focal/metabolismo , Humanos , Antígeno de Macrófago 1/genética , Antígeno de Macrófago 1/metabolismo , Camundongos , Camundongos Knockout , Neutrófilos/enzimologia , Selectina-P/genética , Fosforilação , Rolipram/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Lesões do Sistema Vascular/sangue , Lesões do Sistema Vascular/enzimologia , Quinases da Família src/metabolismo
4.
J Neurosurg Sci ; 58(4): 231-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24637417

RESUMO

AIM: The objective of the study was to examine the effects and possible mechanisms of phosphodiesterase-4 inhibitor Ro 20-1724 on learning and memory impairments induced by ketamine anesthesia. Further, expression the cAMP response element binding proteins (CREB), transcription factors involved in long-term memory, were analyzed in conjunction with these effects of Ro 20-1724. METHODS: Ninety-six immature (21-day-old) Sprague-Dawley rats were divided into eight groups. To assess the learning and memory impairments, Morris Water Maze task was used. Expression of total and phosphorylated CREB in the hippocampus and cerebral cortex was evaluated by Western blot. RESULTS: THE escape latency and frequency of passing the platform in Morris Water Maze task were markedly longer after ketamine anesthesia. However, treatment with Ro 20-1724 significantly (P<0.05) improved both learning and memory performance. Further, administration of Ro 20-1724 reverted the down-regulation of total and phosphorylated CREB caused by ketamine (P<0.05), as demonstrated by Western blot analysis of CREB expression in the hippocampus and cortex. CONCLUSION: Treatment with Ro 20-1724 improves learning and memory deficits caused by ketamine anesthesia in immature rats, possibly via increases in expression of total and phosphorylated CREB in the hippocampus and cerebral cortex.


Assuntos
4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Anestésicos Dissociativos/efeitos adversos , Encéfalo/efeitos dos fármacos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/biossíntese , Ketamina/efeitos adversos , Inibidores de Fosfodiesterase/farmacologia , Animais , Western Blotting , Córtex Cerebral/efeitos dos fármacos , Modelos Animais de Doenças , Regulação para Baixo , Hipocampo/efeitos dos fármacos , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
5.
J Pharmacol Exp Ther ; 349(1): 56-65, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24459245

RESUMO

Elevation of intracellular cAMP and activation of protein kinase A (PKA) lead to activation of large conductance voltage- and Ca(2+)-activated K(+) (BK) channels, thus attenuation of detrusor smooth muscle (DSM) contractility. In this study, we investigated the mechanism by which pharmacological inhibition of cAMP-specific phosphodiesterase 4 (PDE4) with rolipram or Ro-20-1724 (C(15)H(22)N(2)O(3)) suppresses guinea pig DSM excitability and contractility. We used high-speed line-scanning confocal microscopy, ratiometric fluorescence Ca(2+) imaging, and perforated whole-cell patch-clamp techniques on freshly isolated DSM cells, along with isometric tension recordings of DSM isolated strips. Rolipram caused an increase in the frequency of Ca(2+) sparks and the spontaneous transient BK currents (TBKCs), hyperpolarized the cell membrane potential (MP), and decreased the intracellular Ca(2+) levels. Blocking BK channels with paxilline reversed the hyperpolarizing effect of rolipram and depolarized the MP back to the control levels. In the presence of H-89 [N-[2-[[3-(4-bromophenyl)-2-propenyl]amino]ethyl]-5-isoquinolinesulfonamide dihydrochloride], a PKA inhibitor, rolipram did not cause MP hyperpolarization. Rolipram or Ro-20-1724 reduced DSM spontaneous and carbachol-induced phasic contraction amplitude, muscle force, duration, and frequency, and electrical field stimulation-induced contraction amplitude, muscle force, and tone. Paxilline recovered DSM contractility, which was suppressed by pretreatment with PDE4 inhibitors. Rolipram had reduced inhibitory effects on DSM contractility in DSM strips pretreated with paxilline. This study revealed a novel cellular mechanism whereby pharmacological inhibition of PDE4 leads to suppression of guinea pig DSM contractility by increasing the frequency of Ca(2+) sparks and the functionally coupled TBKCs, consequently hyperpolarizing DSM cell MP. Collectively, this decreases the global intracellular Ca(2+) levels and DSM contractility in a BK channel-dependent manner.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/farmacologia , Bexiga Urinária/efeitos dos fármacos , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/administração & dosagem , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Animais , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Polaridade Celular/efeitos dos fármacos , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Estimulação Elétrica , Cobaias , Masculino , Potenciais da Membrana/efeitos dos fármacos , Relaxamento Muscular/fisiologia , Músculo Liso/citologia , Músculo Liso/fisiologia , Inibidores da Fosfodiesterase 4/administração & dosagem , Rolipram/administração & dosagem , Rolipram/farmacologia , Bexiga Urinária/citologia , Bexiga Urinária/fisiologia
6.
Eur J Pharmacol ; 714(1-3): 515-21, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23831390

RESUMO

Phosphodiesterase inhibitors have been reported to be beneficial in cognitive and motor disorders. In the present study, we have investigated the effects of RO 20-1724 (PDE4 inhibitor) and sildenafil (PDE5 inhibitor) in 3-nitropropionic acid (3-NP) induced experimental Huntington's disease in rats. 3-Nitropropionic acid was administered for 14 days (10 mg/kg i.p.) 1h following 3-NP administration, the rats were treated with either vehicle, RO 20-1724 (0.25 and 0.5 mg/kg i.p.) or sildenafil (2 and 4 mg/kg i.p.) for 14 days. Cognitive functions were assessed by using Morris water maze whereas, motor functions were assessed by spontaneous locomotor activity, limb withdrawal and suspended wire test at different time points. Biochemically, markers of oxidative stress and cell damage, such as reduced glutathione, malondialdehyde, nitrite and lactate dehydrogenase levels were assessed terminally in the brain homogenate. Chronic administration of 3-NP produced significant decrease in body weight, showed marked abnormalities in cognitive and motor functions. Further, significant oxidative-nitrosative stress and cell damage was also observed. Chronic administration of RO 20-1724 and sildenafil in 3-NP treated rats significantly and dose dependently attenuated 3-NP induced behavioral and biochemical abnormalities in rats. Both these drugs were equally effective in attenuating 3-NP induced neurotoxicity. These results suggesting that the inhibition of PDE4 and PDE5 would be therapeutic in neurodegenerative disorders associated with cognitive and motor dysfunction.


Assuntos
4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Comportamento Animal/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Nitrocompostos/toxicidade , Inibidores da Fosfodiesterase 4/farmacologia , Inibidores da Fosfodiesterase 5/farmacologia , Piperazinas/farmacologia , Propionatos/toxicidade , Sulfonas/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Encéfalo/metabolismo , Glutationa/metabolismo , L-Lactato Desidrogenase/metabolismo , Malondialdeído/metabolismo , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Memória/efeitos dos fármacos , Purinas/farmacologia , Ratos , Ratos Wistar , Citrato de Sildenafila , Succinato Desidrogenase/metabolismo
7.
Acta Biochim Pol ; 59(3): 371-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22946025

RESUMO

The bronchial epithelium is a very important factor during the inflammatory response, it produces many key regulators involved in the pathophysiology of asthma and COPD. Local influx of eosinophils, basophils, Th2 lymphocytes and macrophages is the source of many cytotoxic proteins, cytokines and other mediators of inflammation. These cells are attracted by eotaxins (eotaxin-1/CCL11, eotaxin-2/CCL24, eotaxin-3/CCL26). Inhibitors of phosphodiesterase 4 (PDE4) are new anti-inflammatory drugs which cause cAMP accumulation in the cell and inhibit numerous stages of allergic inflammation. The aim of our study was to evaluate the influence of PDE4 inhibitors: rolipram and RO-20-1724 on the expression of eotaxins in human primary bronchial epithelial cells. Cells were preincubated with PDE4 inhibitors for 1 hour and then stimulated with IL-4 or IL-13 alone or in combination with TNF-α. After 48 hours, eotaxin protein level was measured by ELISA and mRNA level by real time PCR. These cells produce CCL24 and CCL26. PDE4 inhibitors increased CCL24 and CCL26 mRNA level irrespectively of the used stimulators. Rolipram and RO-20-1724 had no effect on eotaxin protein production in our experimental conditions. Thus PDE4 inhibitors have no effect on eotaxin protein expression in human primary bronchial epithelial cells. In vitro experiments should be performed using a primary cell model rather than immortalized lines.


Assuntos
Brônquios/citologia , Quimiocina CCL24/metabolismo , Quimiocinas CC/metabolismo , Células Epiteliais/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/farmacologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Brônquios/efeitos dos fármacos , Brônquios/metabolismo , Linhagem Celular , Quimiocina CCL24/genética , Quimiocina CCL26 , Quimiocinas CC/genética , Meios de Cultura/metabolismo , Ensaio de Imunoadsorção Enzimática , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Humanos , Interleucina-13/farmacologia , Interleucina-4/farmacologia , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Rolipram/farmacologia , Fatores de Tempo , Fator de Necrose Tumoral alfa/farmacologia
8.
Urology ; 80(4): 952.e9-14, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22901823

RESUMO

OBJECTIVE: To investigate further the potential significance of the cyclic adenosine monophosphate (cAMP) pathway in the control of prostate smooth muscle. The cAMP pathway has been assumed to be an alternative pharmacologic target to treat dysfunctions of the human lower urinary tract. To date, only a few studies have addressed the physiologic relevance of cAMP signal transduction in the control of human prostate function. METHODS: Phosphodiesterase activity was isolated from microsomal fractions prepared from prostatic tissue and subjected to biochemical analysis. Using the organ bath technique, the effects of the phosphodiesterase type (PDE)4 inhibitors Ro 20-1724, rolipram, and RP 73401 on the tension induced by norepinephrine of isolated prostatic tissue were investigated and compared with the PDE5 inhibitor sildenafil and BAY 13-1197, a nitric oxide-independent activator of the soluble guanylyl cyclase. Statistical analysis was conducted using the Gosset t test. RESULTS: Biochemical analysis of the microsomal fraction revealed only a single peak of PDE activity that was sensitive to papaverine and the PDE4 inhibitors rolipram and Ro 20-1724. The tension induced by norepinephrine was reversed by the drugs with the following order of efficacy: Ro 20-1724, RP 73401, rolipram, sildenafil, and BAY 13-1197. Pre-exposure of the tissue to a threshold concentration (0.05 µM) of forskolin (adenlyl cyclase activator) increased the reversion of tension induced by rolipram and RP 73401 and the PDE5 inhibitor sildenafil. CONCLUSION: These results have provided evidence for the significance of cAMP signaling in the control of prostate smooth muscle.


Assuntos
AMP Cíclico/metabolismo , Contração Muscular/efeitos dos fármacos , Músculo Liso/enzimologia , Inibidores de Fosfodiesterase/farmacologia , Próstata/enzimologia , Transdução de Sinais , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Idoso , Benzamidas/farmacologia , Colforsina/farmacologia , Humanos , Técnicas In Vitro , Concentração Inibidora 50 , Masculino , Pessoa de Meia-Idade , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Papaverina/farmacologia , Inibidores da Fosfodiesterase 4/farmacologia , Inibidores da Fosfodiesterase 5/farmacologia , Piperazinas/farmacologia , Próstata/efeitos dos fármacos , Próstata/fisiologia , Purinas/farmacologia , Piridinas/farmacologia , Rolipram/farmacologia , Transdução de Sinais/efeitos dos fármacos , Citrato de Sildenafila , Sulfonas/farmacologia
9.
Pharmacol Biochem Behav ; 101(2): 239-45, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22285388

RESUMO

Cyclic nucleotides viz cGMP and cAMP are known to play an important role in learning and memory processes. Enhancement of cyclic nucleotide signalling through inhibition of phosphodiesterases (PDEs) has been reported to be beneficial in several neurodegenerative disorders associated with cognitive decline. The present study was undertaken to investigate the effect of RO-20-1724-a PDE4 inhibitor on streptozotocin (STZ) induced experimental sporadic dementia of Alzheimer's type. The STZ was injected twice intracerebroventrically (3 mg/kg i.c.v.) on alternate days (day 1 and day 3) in rats. The STZ injected rats were treated with RO-20-1724 (125, 250 and 500 µg/kgi.p.) for 21 days following first i.c.v. STZ administration. Learning and memory in rats were assessed by passive avoidance [PA (days 14 and 15)] and Morris water maze [MWM (days 17, 18, 19, 20 and 21)] following first i.c.v. STZ administration. On day 22 rat cerebral homogenate was used for all the biochemical estimations. The pharmacological inhibition of PDE4 by RO-20-1724 significantly attenuated STZ induced cognitive deficit and oxidative stress. RO-20-1724 was found to not only improve learning and memory in MWM and PA paradigms but also restore STZ induced elevation in cholinesterase activity. Further, RO-20-1724 significantly reduced malondialdehyde and nitrite levels, and restored the glutathione levels indicating attenuation of oxidative stress. Current data complement previous studies by providing evidence for a subset of cognition enhancing effects after PDE4 inhibition. The observed beneficial effects of RO-20-1724 in spatial memory may be due to its ability to restore cholinergic functions and possibly through its antioxidant mechanisms.


Assuntos
4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/administração & dosagem , Transtornos Cognitivos/prevenção & controle , Fármacos Neuroprotetores/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/administração & dosagem , Estreptozocina/toxicidade , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Transtornos Cognitivos/induzido quimicamente , Transtornos Cognitivos/enzimologia , Relação Dose-Resposta a Droga , Injeções Intraventriculares , Masculino , Distribuição Aleatória , Ratos , Ratos Wistar , Estreptozocina/administração & dosagem
10.
J Physiol Pharmacol ; 62(3): 303-11, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21893690

RESUMO

UNLABELLED: The increasing number of eosinophils into bronchoaelvolar space is observed during noninfectious inflammatory lung diseases. Eotaxins (eotaxin-1/CCL11, eotaxin-2/CCL24, eotaxin-3/CCL26) are the strongest chemotactic agents for eosinophils. Inhibitors of phosphodiesterase 4 (PDE4), the enzyme decomposing cAMP, are anti-inflammatory agents which act through cAMP elevation and inhibit numerous steps of allergic inflammation. The effect of PDE4 inhibitors on eotaxin expression is not known in details. The aim of our study was to evaluate the influence of PDE4 inhibitors: rolipram and RO-20-1724 on expression of eotaxins in bronchial epithelial cell line BEAS-2B. Cells were preincubated with PDE4 inhibitors or dexamethasone for 1 hour and then stimulated with IL-4 or IL-13 alone or in combination with TNF-α. After 48 hours eotaxin protein level was measured by ELISA and mRNA level by real time PCR. RESULTS: PDE4 inhibitors decreased CCL11 and CCL26 expression only in cultures co-stimulated with TNF-α. In cultures stimulated with IL-4 and TNF-α rolipram and RO-20-1724 diminished CCL11 mRNA expression by 34 and 37%, respectively, and CCL26 by 43 and 47%. In cultures stimulated with IL-13 and TNF-α rolipram and RO-20-1724 decreased expression of both eotaxins by about 50%. These results were confirmed at the protein level. The effect of PDE4 inhibitors on eotaxin expression in BEAS-2B cells, in our experimental conditions, depends on TNF-α contribution.


Assuntos
4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Quimiocina CCL11/biossíntese , Quimiocina CCL24/biossíntese , Quimiocinas CC/biossíntese , Inibidores da Fosfodiesterase 4/farmacologia , Rolipram/farmacologia , Anti-Inflamatórios/farmacologia , Brônquios/citologia , Brônquios/metabolismo , Técnicas de Cultura de Células , Quimiocina CCL11/genética , Quimiocina CCL24/genética , Quimiocina CCL26 , Quimiocinas CC/genética , Citocinas/metabolismo , Dexametasona/farmacologia , Eosinófilos/metabolismo , Células Epiteliais , Humanos
11.
Psychopharmacology (Berl) ; 218(2): 331-9, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21509503

RESUMO

RATIONALE: Cyclic AMP (cAMP)-protein kinase A signaling has been implicated in the regulation of ethanol consumption. Phosphodiesterase-4 (PDE4) specifically hydrolyzes cAMP and plays a critical role in controlling intracellular cAMP levels in the brain. However, the role of PDE4 in ethanol consumption remains unknown. OBJECTIVE: The objective of this study is to examine whether PDE4 was involved in regulating ethanol intake. METHODS: The two-bottle choice paradigm was used to assess intake of ethanol, sucrose, and quinine in C57BL/6J mice treated with the selective PDE4 inhibitor rolipram or Ro 20-1724; locomotor activity was also monitored using the open-field test in mice treated with rolipram. RESULTS: Administration (i.p.) of either rolipram (0.25 and 0.5 mg/kg) or Ro 20-1724 (10 mg/kg) reduced ethanol intake and preference by 60-80%, but did not alter total fluid intake. In contrast, rolipram even at the higher dose of 0.5 mg/kg was not able to affect intake of sucrose or quinine, alcohol-induced sedation, or blood ethanol elimination. At 0.5 mg/kg, rolipram did decrease locomotor activity, but the effect only lasted for approximately 40 min, which did not likely affect behavior of ethanol drinking. CONCLUSIONS: These results suggest that PDE4 is a novel target for drugs that reduce ethanol intake; PDE4 inhibitors may be used for treatment of alcohol dependence.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Etanol/administração & dosagem , Inibidores da Fosfodiesterase 4/farmacologia , Rolipram/farmacologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/administração & dosagem , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Consumo de Bebidas Alcoólicas/prevenção & controle , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Depressores do Sistema Nervoso Central/administração & dosagem , Depressores do Sistema Nervoso Central/sangue , Depressores do Sistema Nervoso Central/farmacologia , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/efeitos dos fármacos , Relação Dose-Resposta a Droga , Etanol/sangue , Etanol/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Atividade Motora/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/administração & dosagem , Inibidores de Fosfodiesterase/administração & dosagem , Inibidores de Fosfodiesterase/farmacologia , Quinina/administração & dosagem , Rolipram/administração & dosagem , Sacarose/administração & dosagem
12.
Urology ; 76(6): 1518.e1-6, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20970829

RESUMO

OBJECTIVES: To investigate further the role of phosphodiesterase (PDE) isoenzymes in the control of human seminal vesicle (SV) smooth muscle contractility, we examined the functional responses of isolated SV tissue to various PDE inhibitors. It has been suggested that the application of inhibitors of the PDE type 5 may facilitate SV smooth muscle relaxation and, subsequently, retard ejaculatory response. METHODS: Using the organ bath technique, strip preparations of human SV were exposed for 5 minutes to 1 µM of the PDE inhibitors milrinone (PDE3 inhibitor), rolipram, Ro 20-1724 (PDE4 inhibitors), and sildenafil (PDE5 inhibitor). Norepinephrine (NE, alpha agonist) was then added (0,1 µM, 1 µM, and 10 µM) and isometric responses were recorded. A contraction-response curve to NE in the absence of PDE inhibitors was also generated. Drug effects on the production of cyclic adenosine monophosphate (AMP) and cyclic guanosine monophosphate (GMP) were measured by means of radioimmunometric assays. RESULTS: The contraction induced by NE was effectively antagonized by 1 µM of rolipram (83.3% inhibition), Ro 20-1724 (72.3% inhibition), sildenafil (41.6% inhibition), and milrinone (37.5% inhibition). The inhibition of force generation was paralleled by a 1.6-fold to 2.8-fold increase in tissue cyclic AMP (induced by milrinone, rolipram, Ro 20-1724), and a 12-fold rise in cyclic GMP (induced by sildenafil). CONCLUSION: The findings demonstrate that PDE inhibitors can counteract the contraction of human SV mediated by alpha-adrenergic receptors and enhance levels of cyclic nucleotides. This might be of importance with regard to the identification of new options for the pharmacological treatment of premature ejaculation.


Assuntos
AMP Cíclico/biossíntese , GMP Cíclico/biossíntese , Relaxamento Muscular/efeitos dos fármacos , Norepinefrina/antagonistas & inibidores , Inibidores de Fosfodiesterase/farmacologia , Glândulas Seminais/efeitos dos fármacos , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Idoso , Colforsina/farmacologia , Avaliação Pré-Clínica de Medicamentos , Ejaculação/efeitos dos fármacos , Humanos , Técnicas In Vitro , Masculino , Milrinona/farmacologia , Nitroprussiato/farmacologia , Piperazinas/farmacologia , Purinas/farmacologia , Receptores Adrenérgicos alfa/fisiologia , Rolipram/farmacologia , Glândulas Seminais/metabolismo , Citrato de Sildenafila , Sulfonas/farmacologia
13.
Hypertension ; 56(6): 1096-101, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20975032

RESUMO

Our previous studies show that inhibition of phosphodiesterase 4 (PDE4) augments agonist-induced renovascular 3',5'-cAMP secretion more in isolated, perfused kidneys from spontaneously hypertensive rats (SHR) versus Wistar-Kyoto normotensive rats (WKY); however, whether this is because of PDE4 inhibition in renovascular smooth muscle cells or endothelial cells is unknown. Therefore, we examined the effects of 3-isobutyl-1-methylxanthine (broad-spectrum PDE inhibitor) and RO 20-1724 (selective PDE4 inhibitor) on isoproterenol-induced 3',5'-cAMP levels in cultured WKY and SHR preglomerular vascular smooth muscle and endothelial cells. 3-Isobutyl-1-methylxanthine and RO 20-1724 augmented isoproterenol-induced 3',5'-cAMP levels similarly in WKY versus SHR endothelial cells. In contrast, 3-isobutyl-1-methylxanthine and RO 20-1724 augmented isoproterenol-induced 3',5'-cAMP levels significantly more in SHR, compared to WKY, smooth muscle cells (P<0.0001). In both cell types from both rat strains, mRNA levels for the PDE4B subtype exceeded levels for the PDE4A, PDE4C, and PDE4D subtypes, and small interfering RNA knockdown of PDE4B mRNA in SHR smooth muscle cells increased isoproterenol-induced 3',5'-cAMP. mRNA levels for the PDE4B2 variant exceeded levels for the PDE4B1, PDE4B3, PDE4B4, and PDE4B5 variants. In vivo, infusions of RO 20-1724 increased the urinary excretion of 3',5'-cAMP more in SHR than WKY (P=0.0211). We conclude that (1) the greater effect of PDE4 inhibition on renovascular 3',5'-cAMP is mediated by inhibition of PDE4 in renovascular smooth muscle cells, not endothelial cells; (2) the major PDE4 subtype in both renovascular smooth muscle and endothelial cells is PDE4B with variant PDE4B2 likely being dominant; and (3) inhibition of PDE4 in vivo increases renal 3',5'-cAMP levels more in genetically hypertensive rats.


Assuntos
AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Endotélio Vascular/metabolismo , Hipertensão/metabolismo , Rim/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , 1-Metil-3-Isobutilxantina/farmacologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Endotélio Vascular/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Hipertensão/genética , Isoproterenol/farmacologia , Rim/enzimologia , Masculino , Músculo Liso Vascular/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
14.
Neuropsychopharmacology ; 35(7): 1605-17, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20237461

RESUMO

The mossy fiber synapses onto hippocampal CA3 neurons show unique molecular features and a wide dynamic range of plasticity. Although acute stress has been well recognized to alter bidirectional long-term synaptic plasticity in the hippocampal CA1 region and dentate gyrus, it remains unclear whether the same effect may also occur at the mossy fiber-CA3 synapses. Here, we report that hippocampal slices prepared from adult mice that had experienced an acute unpredictable and inescapable restraint tail-shock stress showed a marked impairment of long-term potentiation (LTP) induced by high-frequency stimulation or adenylyl cyclase activator forskolin. This effect was prevented when animals were submitted to bilateral adrenalectomy or given the glucocorticoid receptor antagonist RU38486 before experiencing stress. In contrast, stress has no effect on synaptic potentiation induced by the non-hydrolysable and membrane-permeable cyclic adenosine 5'-monophosphate (cAMP) analog Sp-8-bromo-cAMPS. No obvious differences were observed between control and stressed mice in the basal synaptic transmission, paired-pulse facilitation, or frequency facilitation at the mossy fiber-CA3 synapses. We also found that the inhibitory effect of stress on mossy fiber LTP was obviated by the adenosine A(1) receptor antagonist 8-cyclopentyl-1,3,-dipropylxanthine, the non-specific phosphodiesterase (PDE) inhibitor 3-isobutyl-methylxanthine, and the specific PDE4 inhibitor 4-(3-butoxy-4-methoxyphenyl)methyl-2-imidazolidone. In addition, stress induces a sustained and profound increase in cAMP-specific PDE4 activity. These results suggest that the inhibition of mossy fiber LTP by acute stress treatment seems originating from a corticosterone-induced sustained increase in the PDE4 activity to accelerate the metabolism of cAMP to adenosine, in turn triggering an adenosine A(1) receptor-mediated impairment of transmitter release machinery.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Hipocampo/patologia , Potenciação de Longa Duração/fisiologia , Fibras Musgosas Hipocampais/fisiopatologia , Estresse Psicológico/patologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Adrenalectomia/métodos , Animais , Anti-Inflamatórios/administração & dosagem , Fenômenos Biofísicos/efeitos dos fármacos , Colforsina/farmacologia , Corticosterona/administração & dosagem , Corticosterona/sangue , AMP Cíclico/farmacologia , Estimulação Elétrica , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Hipocampo/efeitos dos fármacos , Técnicas In Vitro , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Antagonistas de Receptores de Mineralocorticoides/administração & dosagem , Inibidores de Fosfodiesterase/administração & dosagem , Espironolactona/administração & dosagem , Espironolactona/análogos & derivados , Estresse Psicológico/prevenção & controle , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo , Xantinas/farmacologia
15.
Br J Pharmacol ; 159(2): 353-61, 2010 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-20082613

RESUMO

BACKGROUND AND PURPOSE: Phosphodiesterase (PDE) inhibitors are useful to treat hypoxia-related diseases and are used in experiments studying the effects of oxygen on 3'-5'-cyclic adenosine monophosphate (cAMP) production. We studied the effects of acute hypoxia on cAMP accumulation induced by PDE inhibitors in oxygen-specific chemosensors, the carotid bodies (CBs) and in non-chemosensitive CB-related structures: carotid arteries (CAs) and superior cervical ganglia (SCG). EXPERIMENTAL APPROACH: Concentration-response curves for the effects of a non-specific PDE inhibitor [isobutylmethylxanthine (IBMX) ], PDE4 selective inhibitors (rolipram, Ro 20-1724) and a PDE2 selective inhibitor (erythro-9-(2-hydroxy-3-nonyl)adenine) on cAMP levels were obtained in normoxic (20% O(2)/5% CO(2)) or hypoxic (5% O(2)/5% CO(2)) conditions. KEY RESULTS: Responses to the PDE inhibitors were compatible with the presence of PDE4 in rat CBs, CAs and SCG but in the absence of PDE2 in CAs and CBs. Acute hypoxia enhanced the effects of IBMX and PDE4 inhibitors on cAMP accumulation in CAs and CBs. In SCG, acute hypoxia reduced cAMP accumulation induced by all the four PDE inhibitors tested. Differences between the effects of Ro 20-1724 and rolipram on cAMP were found in CAs and CBs during hypoxia. CONCLUSIONS AND IMPLICATIONS: The effects of PDE4 inhibitors could be potentiated or inhibited by acute hypoxia depending on the PDE isoforms of the tissue. The similarities between the characterization of PDE4 inhibitors at the CBs and CAs, under normoxia and hypoxia, did not support a specific role for cAMP in the oxygen-sensing machinery at the CB and suggested that no direct CB-mediated, hyperventilatory, adverse effects would be expected with administration of PDE4 inhibitors.


Assuntos
Artérias Carótidas/efeitos dos fármacos , Corpo Carotídeo/efeitos dos fármacos , AMP Cíclico/metabolismo , Oxigênio/farmacologia , Inibidores da Fosfodiesterase 4 , Gânglio Cervical Superior/efeitos dos fármacos , 1-Metil-3-Isobutilxantina/farmacologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Animais , Artérias Carótidas/metabolismo , Corpo Carotídeo/metabolismo , Hipóxia Celular , Feminino , Técnicas In Vitro , Masculino , Ratos , Ratos Wistar , Rolipram/farmacologia , Gânglio Cervical Superior/metabolismo
16.
Circ Res ; 105(8): 784-92, 2009 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-19745166

RESUMO

RATIONALE: Multiple cyclic nucleotide phosphodiesterases (PDEs) degrade cAMP in cardiomyocytes but the role of PDEs in controlling cAMP signaling during pathological cardiac hypertrophy is poorly defined. OBJECTIVE: Evaluate the beta-adrenergic regulation of cardiac contractility and characterize the changes in cardiomyocyte cAMP signals and cAMP-PDE expression and activity following cardiac hypertrophy. METHODS AND RESULTS: Cardiac hypertrophy was induced in rats by thoracic aortic banding over a time period of 5 weeks and was confirmed by anatomic measurements and echocardiography. Ex vivo myocardial function was evaluated in Langendorff-perfused hearts. Engineered cyclic nucleotide-gated (CNG) channels were expressed in single cardiomyocytes to monitor subsarcolemmal cAMP using whole-cell patch-clamp recordings of the associated CNG current (I(CNG)). PDE variant activity and protein level were determined in purified cardiomyocytes. Aortic stenosis rats exhibited a 67% increase in heart weight compared to sham-operated animals. The inotropic response to maximal beta-adrenergic stimulation was reduced by approximately 54% in isolated hypertrophied hearts, along with a approximately 32% decrease in subsarcolemmal cAMP levels in hypertrophied myocytes. Total cAMP hydrolytic activity as well as PDE3 and PDE4 activities were reduced in hypertrophied myocytes, because of a reduction of PDE3A, PDE4A, and PDE4B, whereas PDE4D was unchanged. Regulation of beta-adrenergic cAMP signals by PDEs was blunted in hypertrophied myocytes, as demonstrated by the diminished effects of IBMX (100 micromol/L) and of both the PDE3 inhibitor cilostamide (1 micromol/L) and the PDE4 inhibitor Ro 201724 (10 micromol/L). CONCLUSIONS: Beta-adrenergic desensitization is accompanied by a reduction in cAMP-PDE and an altered modulation of beta-adrenergic cAMP signals in cardiac hypertrophy.


Assuntos
Cardiomegalia/enzimologia , AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Regulação Enzimológica da Expressão Gênica , Miócitos Cardíacos/enzimologia , Sistemas do Segundo Mensageiro , 1-Metil-3-Isobutilxantina/farmacologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Animais , Estenose da Valva Aórtica/enzimologia , Estenose da Valva Aórtica/patologia , Cardiomegalia/patologia , Células Cultivadas , Relação Dose-Resposta a Droga , Masculino , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/patologia , Tamanho do Órgão , Inibidores da Fosfodiesterase 4 , Inibidores de Fosfodiesterase/farmacologia , Quinolonas/farmacologia , Ratos , Ratos Wistar
17.
Hypertension ; 54(2): 270-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19528365

RESUMO

This study tested the hypothesis that regulation of 3',5'-cAMP levels in the kidney vasculature is abnormal in spontaneously hypertensive rats. In isolated, perfused kidneys from adult rats (16 weeks of age), isoproterenol similarly increased renal venous 3',5'-cAMP secretion from kidneys of hypertensive versus normotensive Wistar-Kyoto rats. However, a broad-spectrum phosphodiesterase inhibitor (isobutyl-1-methylxanthine) augmented isoproterenol (3 mumol/L)-induced increases in renal venous 3',5'-cAMP secretion more so in kidneys from adult hypertensive versus age-matched normotensive rats (31-fold and 5-fold, respectively; P<0.0001). In contrast to isoproterenol, broad-spectrum phosphodiesterase inhibition augmented forskolin-induced increases in renal venous 3',5'-cAMP secretion similarly in kidneys from adult hypertensive versus age-matched normotensive rats. In kidneys from adults of both strains, the effects of isobutyl-1-methylxanthine on isoproterenol-induced 3',5'-cAMP responses were mimicked by the inhibition of phosphodiesterase 4 (RO 20-1724) but not by the inhibition of phosphodiesterase 1 (3,8-methoxymethyl-3-isobutyl-1-methylxanthine) or phosphodiesterase 3 (milrinone). In kidneys from young (5 weeks of age), adult, and old (39 weeks of age) rats, RO 20-1724 augmented isoproterenol-induced renal 3',5'-cAMP secretion more so in kidneys from hypertensive rats. In adult hypertensive rats, arterial blood pressure and renal vascular resistance were elevated compared with age-matched normotensive rats, and intravenous infusions of RO 20-1724 reduced blood pressure and renal vascular resistance in hypertensive rats but had little effect on these variables in normotensive rats. We conclude that, in the renal vasculature of spontaneously hypertensive rats (young, adult, and old), there is increased activity of a compartment of phosphodiesterase 4. Selective inhibition of renal vascular phosphodiesterase 4 may represent a new strategy for improving renal hemodynamics in genetic hypertension.


Assuntos
Colforsina/farmacologia , AMP Cíclico/metabolismo , Hipertensão Renovascular/fisiopatologia , Isoproterenol/farmacologia , Circulação Renal/efeitos dos fármacos , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Análise de Variância , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Determinação da Pressão Arterial , Modelos Animais de Doenças , Hipertensão Renovascular/tratamento farmacológico , Rim/irrigação sanguínea , Rim/efeitos dos fármacos , Rim/fisiopatologia , Masculino , Probabilidade , Distribuição Aleatória , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Valores de Referência , Circulação Renal/fisiologia , Sensibilidade e Especificidade , Xantinas/farmacologia
18.
PLoS One ; 4(3): e4902, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19295914

RESUMO

Adenosine, prostaglandin E(2), or increased intracellular cyclic AMP concentration each elicit potent anti-inflammatory events in human neutrophils by inhibiting functions such as phagocytosis, superoxide production, adhesion and cytokine release. However, the endogenous molecular pathways mediating these actions are poorly understood. In the present study, we examined their impact on the gene expression profile of stimulated neutrophils. Purified blood neutrophils from healthy donors were stimulated with a cocktail of inflammatory agonists in the presence of at least one of the following anti-inflammatory agents: adenosine A(2A) receptor agonist CGS 21680, prostaglandin E(2), cyclic-AMP-elevating compounds forskolin and RO 20-1724. Total RNA was analyzed using gene chips and real-time PCR. Genes encoding transcription factors, enzymes and regulatory proteins, as well as secreted cytokines/chemokines showed differential expression. We identified 15 genes for which the anti-inflammatory agents altered mRNA levels. The agents affected the expression profile in remarkably similar fashion, suggesting a central mechanism limiting cell activation. We have identified a set of genes that may be part of important resolution pathways that interfere with cell activation. Identification of these pathways will improve understanding of the capacity of tissues to terminate inflammatory responses and contribute to the development of therapeutic strategies based on endogenous resolution.


Assuntos
Anti-Inflamatórios/farmacologia , Expressão Gênica/efeitos dos fármacos , Neutrófilos , Transdução de Sinais/fisiologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Adenosina/análogos & derivados , Adenosina/farmacologia , Animais , Anti-Hipertensivos/farmacologia , Colforsina/farmacologia , Dinoprostona/farmacologia , Perfilação da Expressão Gênica , Humanos , Lipopolissacarídeos/farmacologia , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Ocitócicos/farmacologia , Fenetilaminas/farmacologia , Inibidores de Fosfodiesterase/farmacologia
19.
Am J Physiol Heart Circ Physiol ; 296(3): H728-34, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19151257

RESUMO

Downregulation of the sarcoplasmic reticulum calcium ATPase (SERCA2) is associated with diastolic dysfunction in the failing heart. Elevated plasma endothelin-1 (ET) levels are correlated with congestive heart failure suggesting that ET may play a pathophysiological role. We have investigated the ability of ET to regulate SERCA2 gene expression in isolated adult rat ventricular myocytes. We find that ET enhances net protein synthesis by approximately 40% but significantly downregulates SERCA2 mRNA expression, time dependently, by approximately 30-50%, and the expression of SERCA2 protein by approximately 50%. In myoyctes, ET binds to ET(A) receptor that couples to G(q) and G(i) proteins. Inhibition of G(q)-PLC-induced phosphoinositide (PI) hydrolysis with U73122 (1 muM) or inhibition of G(i) protein with pertussis toxin (PTX) abolishes the ability of ET to downregulate SERCA2 mRNA gene expression. Further investigation suggests that ET coupling to PTX-sensitive G(i) with consequent lowering of cAMP is required for downregulation of SERCA2 mRNA levels. Increasing intracellular cAMP quantity using cAMP-specific PDE inhibitor Ro20-1724 or cAMP analog dibutyryl-cAMP reverses ET-induced downregulation of SERCA2 mRNA levels. The data indicate that, in adult myocytes, ET downregulates SERCA2 mRNA and protein levels, and the effect requires cross-talk between G(q) and PTX-sensitive G(i) pathways.


Assuntos
AMP Cíclico/metabolismo , Endotelina-1/metabolismo , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Miócitos Cardíacos/enzimologia , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Animais , Células Cultivadas , CMP Cíclico/análogos & derivados , CMP Cíclico/farmacologia , Regulação para Baixo , Estrenos/farmacologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/antagonistas & inibidores , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/genética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Ventrículos do Coração/enzimologia , Masculino , Mutação , Miócitos Cardíacos/efeitos dos fármacos , Toxina Pertussis/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Pirrolidinonas/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor de Endotelina A/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Transfecção , Fosfolipases Tipo C/antagonistas & inibidores , Fosfolipases Tipo C/metabolismo
20.
Neurosci Lett ; 449(1): 71-5, 2009 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-18983892

RESUMO

Brain pericytes are known to embrace the abluminal endothelial surfaces of cerebral microvessels. The rich expression of contractile proteins in these cells suggests pericytal regulation of cerebral blood flow. Here, we investigated the molecular mechanisms by which an endothelium-derived relaxing factor, adrenomedullin, was able to induce the relaxation of rat primary cultured brain pericytes. Adrenomedullin increased the relative proportion of pericytes that were relaxed, as shown by an increased cell surface area. A smaller fragment of adrenomedullin (adrenomedullin(22-52)) blocked the adrenomedullin-induced relaxation. Adrenomedullin increased intracellular cAMP concentrations and decreased the phosphorylation of myosin light chain (MLC). H89 (a PKA inhibitor) inhibited the adrenomedullin-induced increase in the number of relaxed pericytes, and returned the level of phosphorylation of MLC to the control level. The results of the present study suggest that adrenomedullin-induced relaxation of brain pericytes is related to the reduced phosphorylation of MLC through cAMP/PKA.


Assuntos
Adrenomedulina/farmacologia , Encéfalo/citologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , AMP Cíclico/metabolismo , Cadeias Leves de Miosina/metabolismo , Pericitos/efeitos dos fármacos , Vasodilatadores/farmacologia , 4-(3-Butoxi-4-metoxibenzil)-2-imidazolidinona/farmacologia , Animais , Células Cultivadas , AMP Cíclico/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Isoquinolinas/farmacologia , Pericitos/metabolismo , Fosforilação/efeitos dos fármacos , Ratos , Transdução de Sinais/efeitos dos fármacos , Sulfonamidas/farmacologia , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...