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https://hdl.handle.net/1822/67941
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Campo DC | Valor | Idioma |
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dc.contributor.author | Rocha-Sousa, A. | por |
dc.contributor.author | Saraiva, J. | por |
dc.contributor.author | Henriques-Coelho, T. | por |
dc.contributor.author | Falcão-Reis, F. | por |
dc.contributor.author | Correia-Pinto, Jorge | por |
dc.contributor.author | Leite-Moreira, A. F. | por |
dc.date.accessioned | 2020-10-30T16:29:03Z | - |
dc.date.available | 2020-10-30T16:29:03Z | - |
dc.date.issued | 2006-11 | - |
dc.identifier.citation | Rocha-Sousa, A., Saraiva, J., Henriques-Coelho, T., Falcao-Reis, F., Correia-Pinto, J., & Leite-Moreira, A. F. (2006). Ghrelin as a novel locally produced relaxing peptide of the iris sphincter and dilator muscles. Experimental eye research, 83(5), 1179-1187 | por |
dc.identifier.issn | 0014-4835 | por |
dc.identifier.uri | https://hdl.handle.net/1822/67941 | - |
dc.description.abstract | Ghrelin is a recently described acylated peptide, which works as a somatosecretagogue and has described effects on the smooth, skeletal and cardiac muscle. We examined the production and effects of ghrelin on relaxation of the iris muscles. Contractile effects of 1-5 human ghrelin (frGhr, 10(-9)-6 x 10(-5)M) and 1-5 human des-octanoyl-ghrelin (d-frGhr; 10(-9)-6 x 10(-5)M) were tested on iris rabbit sphincter (n=11 frGhr; n=7 d-frGhr), dilator (n=6 frGhr; n=6 d-frGhr) and rat sphincter (n=6 frGhr; n=8 d-frGhr) precontracted muscles. On rabbit sphincter the effect of frGhr was also tested in presence of: i) L-NA (10(-5)M; n=7); ii) indomethacin (10(-5)M; n=7); iii) DLys(3)GHRP6 (10(-4)M; n=6); and iv) apamin+carybdotoxin (10(-6)M; n=6). Furthermore, on rabbit dilator the effect of frGhr was tested in presence of DLys(3)GHRP6 (10(-4)M; n=7). Finally, ghrelin mRNA production was assessed by "in situ" hybridization in Wistar rat eyes (n=8). In all muscles, frGhr promoted a concentration-dependent relaxation, maximal at 6 x 10(-5)M, 1.5-3 min after its addition, decreasing tension by 34.1+/-12.1%, 25.8+/-4.8% and 52.1+/-10.3% in the rabbit sphincter, dilator and rat sphincter, respectively. In the rabbit sphincter the relaxing effects of frGhr were: (i) enhanced in presence of DLys(3)GHRP6 (118.1+/-21.1%); (ii) blunted by indomethacin; and (iii) not altered by apamin+carybdotoxin (36.4+/-14.4%) or L-NA (52.4+/-11.4%). Relaxing effects of d-frGhr in rabbit (43.3+/-5.2%) and rat (77.1+/-15.3%) sphincter muscles were similar to those of frGhr. In rabbit dilator muscle, d-frGhr did not significantly alter active tension and the relaxing effect of frGhr was blunted by GHSR-1a blockage. Ghrelin mRNA was identified in iris posterior epithelium. In conclusion, ghrelin is a novel, locally produced, relaxing agent of iris dilator and sphincter muscles, an effect that is mediated by GHSR-1a in the former, but not in the latter. Furthermore, in the sphincter it seems to be mediated by prostaglandins, but not by NO or K(Ca) channels. | por |
dc.description.sponsorship | Portuguese Foundation for Science and Technology (nr. POCI/SAU-FCF/60803/2004) through Cardiovascular R&D Unit (FCT nr. 51/94). Authors are sincerely grateful to RS. Moura (SFRH/BPD/15408/2005), Development Unit, Health and Life Sciences Institute, School of Health Sciences, University of Minho, Braga, Portugal for her excellent contribution in the in-situ hybridization techniques. | por |
dc.language.iso | eng | por |
dc.publisher | Academic Press | por |
dc.relation | SFRH/BPD/15408/2005 | - |
dc.rights | openAccess | por |
dc.subject | Animals | por |
dc.subject | Anterior Eye Segment | por |
dc.subject | Carbachol | por |
dc.subject | Cholinergic Agonists | por |
dc.subject | Dose-Response Relationship, Drug | por |
dc.subject | Epinephrine | por |
dc.subject | Ghrelin | por |
dc.subject | In Situ Hybridization | por |
dc.subject | Iris | por |
dc.subject | Male | por |
dc.subject | Muscle Contraction | por |
dc.subject | Muscle Relaxation | por |
dc.subject | Oculomotor Muscles | por |
dc.subject | Oligopeptides | por |
dc.subject | Peptide Hormones | por |
dc.subject | Potassium Channels | por |
dc.subject | Prostaglandin-Endoperoxide Synthases | por |
dc.subject | RNA, Messenger | por |
dc.subject | Rabbits | por |
dc.subject | Rats | por |
dc.subject | Rats, Wistar | por |
dc.subject | Receptors, G-Protein-Coupled | por |
dc.subject | Receptors, Ghrelin | por |
dc.subject | Peptide hormones | por |
dc.subject | Iris | por |
dc.subject | Ciliary epithelium | por |
dc.subject | Muscle fibers | por |
dc.title | Ghrelin as a novel locally produced relaxing peptide of the iris sphincter and dilator muscles | por |
dc.type | article | por |
dc.peerreviewed | yes | por |
dc.relation.publisherversion | https://www.sciencedirect.com/science/article/pii/S0014483506002946 | por |
oaire.citationStartPage | 1179 | por |
oaire.citationEndPage | 1187 | por |
oaire.citationIssue | 5 | por |
oaire.citationVolume | 83 | por |
dc.identifier.doi | 10.1016/j.exer.2006.06.005 | por |
dc.identifier.pmid | 16904667 | por |
dc.subject.fos | Ciências Médicas::Medicina Básica | por |
dc.subject.wos | Science & Technology | por |
sdum.journal | Experimental Eye Research | por |
Aparece nas coleções: | ICVS - Artigos em revistas internacionais / Papers in international journals |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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Rocha-sousa-2006-Ghrelin-as-a-novel-locally-produced.pdf | 274,97 kB | Adobe PDF | Ver/Abrir |