Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary
Autor(a) principal: | |
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Data de Publicação: | 2006 |
Outros Autores: | , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFPA |
Texto Completo: | http://repositorio.ufpa.br/jspui/handle/2011/3291 |
Resumo: | In previous studies, we demonstrated biphasic purinergic effects on prolactin (PRL) secretion stimulated by an adenosine A2 agonist. In the present study, we investigated the role of the activation of adenosine A1 receptors by (R)-N6-(2-phenylisopropyl)adenosine (R-PIA) at the pituitary level in in vitro PRL secretion. Hemipituitaries (one per cuvette in five replicates) from adult male rats were incubated. Administration of R-PIA (0.001, 0.01, 0.1, 1, and 10 µM) induced a reduction of PRL secretion into the medium in a U-shaped dose-response curve. The maximal reduction was obtained with 0.1 µM R-PIA (mean ± SEM, 36.01 ± 5.53 ng/mg tissue weight (t.w.)) treatment compared to control (264.56 ± 15.46 ng/mg t.w.). R-PIA inhibition (0.01 µM = 141.97 ± 15.79 vs control = 244.77 ± 13.79 ng/mg t.w.) of PRL release was blocked by 1 µM cyclopentyltheophylline, a specific A1 receptor antagonist (1 µM = 212.360 ± 26.560 ng/mg t.w.), whereas cyclopentyltheophylline alone (0.01, 0.1, 1 µM) had no effect. R-PIA (0.001, 0.01, 0.1, 1 µM) produced inhibition of PRL secretion stimulated by both phospholipase C (0.5 IU/mL; 977.44 ± 76.17 ng/mg t.w.) and dibutyryl cAMP (1 mM; 415.93 ± 37.66 ng/mg t.w.) with nadir established at the dose of 0.1 µM (225.55 ± 71.42 and 201.9 ± 19.08 ng/mg t.w., respectively). Similarly, R-PIA (0.01 µM) decreased (242.00 ± 24.00 ng/mg t.w.) the PRL secretion stimulated by cholera toxin (0.5 mg/mL; 1050.00 ± 70.00 ng/mg t.w.). In contrast, R-PIA had no effect (468.00 ± 34.00 ng/mg t.w.) on PRL secretion stimulation by pertussis toxin (0.5 mg/mL; 430.00 ± 26.00 ng/mg t.w.). These results suggest that inhibition of PRL secretion after A1 receptor activation by R-PIA is mediated by a Gi protein-dependent mechanism. |
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2012-12-20T15:32:37Z2012-12-20T15:32:37Z2006-11PICANÇO-DINIZ, D.L.W.; VALENÇA, M.M.; ANTUNES-RODRIGUES, J. Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary. Brazilian Journal of Medical and Biological Research, Ribeirão Preto, v. 39, n. 11, p. 1493-1499, nov. 2006. Disponível em: <http://www.scielo.br/pdf/bjmbr/v39n11/6262.pdf>. Acesso em: 11 dez. 2012.1414-431Xhttp://repositorio.ufpa.br/jspui/handle/2011/3291In previous studies, we demonstrated biphasic purinergic effects on prolactin (PRL) secretion stimulated by an adenosine A2 agonist. In the present study, we investigated the role of the activation of adenosine A1 receptors by (R)-N6-(2-phenylisopropyl)adenosine (R-PIA) at the pituitary level in in vitro PRL secretion. Hemipituitaries (one per cuvette in five replicates) from adult male rats were incubated. Administration of R-PIA (0.001, 0.01, 0.1, 1, and 10 µM) induced a reduction of PRL secretion into the medium in a U-shaped dose-response curve. The maximal reduction was obtained with 0.1 µM R-PIA (mean ± SEM, 36.01 ± 5.53 ng/mg tissue weight (t.w.)) treatment compared to control (264.56 ± 15.46 ng/mg t.w.). R-PIA inhibition (0.01 µM = 141.97 ± 15.79 vs control = 244.77 ± 13.79 ng/mg t.w.) of PRL release was blocked by 1 µM cyclopentyltheophylline, a specific A1 receptor antagonist (1 µM = 212.360 ± 26.560 ng/mg t.w.), whereas cyclopentyltheophylline alone (0.01, 0.1, 1 µM) had no effect. R-PIA (0.001, 0.01, 0.1, 1 µM) produced inhibition of PRL secretion stimulated by both phospholipase C (0.5 IU/mL; 977.44 ± 76.17 ng/mg t.w.) and dibutyryl cAMP (1 mM; 415.93 ± 37.66 ng/mg t.w.) with nadir established at the dose of 0.1 µM (225.55 ± 71.42 and 201.9 ± 19.08 ng/mg t.w., respectively). Similarly, R-PIA (0.01 µM) decreased (242.00 ± 24.00 ng/mg t.w.) the PRL secretion stimulated by cholera toxin (0.5 mg/mL; 1050.00 ± 70.00 ng/mg t.w.). In contrast, R-PIA had no effect (468.00 ± 34.00 ng/mg t.w.) on PRL secretion stimulation by pertussis toxin (0.5 mg/mL; 430.00 ± 26.00 ng/mg t.w.). These results suggest that inhibition of PRL secretion after A1 receptor activation by R-PIA is mediated by a Gi protein-dependent mechanism.engDibutirilCAMPTeofilina ciclopentiloColera toxinaPertussis toxinaAdenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitaryinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleDINIZ, Domingos Luiz Wanderley PicançoVALENÇA, Marcelo MoraesRODRIGUES, José Antunesinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFPAinstname:Universidade Federal do Pará (UFPA)instacron:UFPAORIGINALArtigo_AdenosineReceptorMediated.pdfArtigo_AdenosineReceptorMediated.pdfapplication/pdf507765http://repositorio.ufpa.br/oai/bitstream/2011/3291/1/Artigo_AdenosineReceptorMediated.pdfa097c4721efad77c29fa660666ddb63cMD51CC-LICENSElicense_urllicense_urltext/plain; charset=utf-849http://repositorio.ufpa.br/oai/bitstream/2011/3291/2/license_urlfd26723f8d7edacdb29e3f03465c3b03MD52license_textlicense_texttext/html; charset=utf-80http://repositorio.ufpa.br/oai/bitstream/2011/3291/3/license_textd41d8cd98f00b204e9800998ecf8427eMD53license_rdflicense_rdfapplication/rdf+xml; charset=utf-823599http://repositorio.ufpa.br/oai/bitstream/2011/3291/4/license_rdf9e2b7f6edbd693264102b96ece20428aMD54LICENSElicense.txtlicense.txttext/plain; charset=utf-82012http://repositorio.ufpa.br/oai/bitstream/2011/3291/5/license.txtcd821bd92717df12c0e7cf48f7bc1694MD55TEXTArtigo_AdenosineReceptorMediated.pdf.txtArtigo_AdenosineReceptorMediated.pdf.txtExtracted texttext/plain24360http://repositorio.ufpa.br/oai/bitstream/2011/3291/6/Artigo_AdenosineReceptorMediated.pdf.txtd469052b9e88698507d672d64467f610MD562011/32912018-01-10 13:55:41.198oai:repositorio.ufpa.br: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Repositório InstitucionalPUBhttp://repositorio.ufpa.br/oai/requestriufpabc@ufpa.bropendoar:21232018-01-10T16:55:41Repositório Institucional da UFPA - Universidade Federal do Pará (UFPA)false |
dc.title.pt_BR.fl_str_mv |
Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary |
title |
Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary |
spellingShingle |
Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary DINIZ, Domingos Luiz Wanderley Picanço Dibutiril CAMP Teofilina ciclopentilo Colera toxina Pertussis toxina |
title_short |
Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary |
title_full |
Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary |
title_fullStr |
Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary |
title_full_unstemmed |
Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary |
title_sort |
Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary |
author |
DINIZ, Domingos Luiz Wanderley Picanço |
author_facet |
DINIZ, Domingos Luiz Wanderley Picanço VALENÇA, Marcelo Moraes RODRIGUES, José Antunes |
author_role |
author |
author2 |
VALENÇA, Marcelo Moraes RODRIGUES, José Antunes |
author2_role |
author author |
dc.contributor.author.fl_str_mv |
DINIZ, Domingos Luiz Wanderley Picanço VALENÇA, Marcelo Moraes RODRIGUES, José Antunes |
dc.subject.por.fl_str_mv |
Dibutiril CAMP Teofilina ciclopentilo Colera toxina Pertussis toxina |
topic |
Dibutiril CAMP Teofilina ciclopentilo Colera toxina Pertussis toxina |
description |
In previous studies, we demonstrated biphasic purinergic effects on prolactin (PRL) secretion stimulated by an adenosine A2 agonist. In the present study, we investigated the role of the activation of adenosine A1 receptors by (R)-N6-(2-phenylisopropyl)adenosine (R-PIA) at the pituitary level in in vitro PRL secretion. Hemipituitaries (one per cuvette in five replicates) from adult male rats were incubated. Administration of R-PIA (0.001, 0.01, 0.1, 1, and 10 µM) induced a reduction of PRL secretion into the medium in a U-shaped dose-response curve. The maximal reduction was obtained with 0.1 µM R-PIA (mean ± SEM, 36.01 ± 5.53 ng/mg tissue weight (t.w.)) treatment compared to control (264.56 ± 15.46 ng/mg t.w.). R-PIA inhibition (0.01 µM = 141.97 ± 15.79 vs control = 244.77 ± 13.79 ng/mg t.w.) of PRL release was blocked by 1 µM cyclopentyltheophylline, a specific A1 receptor antagonist (1 µM = 212.360 ± 26.560 ng/mg t.w.), whereas cyclopentyltheophylline alone (0.01, 0.1, 1 µM) had no effect. R-PIA (0.001, 0.01, 0.1, 1 µM) produced inhibition of PRL secretion stimulated by both phospholipase C (0.5 IU/mL; 977.44 ± 76.17 ng/mg t.w.) and dibutyryl cAMP (1 mM; 415.93 ± 37.66 ng/mg t.w.) with nadir established at the dose of 0.1 µM (225.55 ± 71.42 and 201.9 ± 19.08 ng/mg t.w., respectively). Similarly, R-PIA (0.01 µM) decreased (242.00 ± 24.00 ng/mg t.w.) the PRL secretion stimulated by cholera toxin (0.5 mg/mL; 1050.00 ± 70.00 ng/mg t.w.). In contrast, R-PIA had no effect (468.00 ± 34.00 ng/mg t.w.) on PRL secretion stimulation by pertussis toxin (0.5 mg/mL; 430.00 ± 26.00 ng/mg t.w.). These results suggest that inhibition of PRL secretion after A1 receptor activation by R-PIA is mediated by a Gi protein-dependent mechanism. |
publishDate |
2006 |
dc.date.issued.fl_str_mv |
2006-11 |
dc.date.accessioned.fl_str_mv |
2012-12-20T15:32:37Z |
dc.date.available.fl_str_mv |
2012-12-20T15:32:37Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
PICANÇO-DINIZ, D.L.W.; VALENÇA, M.M.; ANTUNES-RODRIGUES, J. Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary. Brazilian Journal of Medical and Biological Research, Ribeirão Preto, v. 39, n. 11, p. 1493-1499, nov. 2006. Disponível em: <http://www.scielo.br/pdf/bjmbr/v39n11/6262.pdf>. Acesso em: 11 dez. 2012. |
dc.identifier.uri.fl_str_mv |
http://repositorio.ufpa.br/jspui/handle/2011/3291 |
dc.identifier.issn.none.fl_str_mv |
1414-431X |
identifier_str_mv |
PICANÇO-DINIZ, D.L.W.; VALENÇA, M.M.; ANTUNES-RODRIGUES, J. Adenosine A1 receptor-mediated inhibition of in vitro prolactin secretion from the rat anterior pituitary. Brazilian Journal of Medical and Biological Research, Ribeirão Preto, v. 39, n. 11, p. 1493-1499, nov. 2006. Disponível em: <http://www.scielo.br/pdf/bjmbr/v39n11/6262.pdf>. Acesso em: 11 dez. 2012. 1414-431X |
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http://repositorio.ufpa.br/jspui/handle/2011/3291 |
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eng |
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eng |
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