The fate of isoprenaline in the isolated rabbit aorta

• Tipo: Artigo em Revista Científica Internacional
• Data: 1981

Autores

Branco, D (Autor) Outra; Azevedo, I (Autor) Outra; Sarmento A (Autor) FMUP; Osswald, W (Autor) Outra

Revista

Título: Naunyn-Schmiedeberg's Archives of Pharmacology

Vol. 316

Páginas: 120-125

ISSN: 0028-1298

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 16 Citações

Scopus - 12 Citações

Outras Informações

ID Authenticus: P-00J-9HC

DOI: 10.1007/bf00505304

Abstract (EN): The fate of isoprenaline (ISO) was studied in the intact rabbit aorta, as well as in the isolated adventitia and isolated media, by means of liquid scintillation counting of 3H-ISO and 3H-O-methylisoprenaline (OMI) as well as by autoradiography of tissues incubated with 2¿M ISO. The 3 preparations accumulated and O-methylated ISO; O-methylation was proportionally higher in the intact vessel than in its constituents. The isolated adventitia differed from the other preparations in reaching a steady-state of cortexone-resistant accumulation after 8 min of incubation and in exhibiting an O-methylating capacity which was partly resistant to the COMT inhibitor, U-0521. The effect of cocaine gave evidence for a participation of neuronal uptake in the accumulation of the amine in the intact aorta. In the media, most of the accumulation occurred in smooth muscle cells and was reduced by cortexone and increased by U-0521; elastin and collagen, present both in the media and the adventitia, showed accumulation which was not affected by the inhibitory drugs studied. The results show that in the rabbit aorta there is a corticosteroid-resistant uptake mechanism (which predominates in the adventitia) which involves structures devoid of COMT activity. Furthermore, smooth muscle cells represent, in the media, the extraneuronal metabolizing site of loss. The adventitia is a complex layer, with different types of cells which may intervene in accumulation and metabolism of ISO. Therefore, it is concluded that the isolated media represents an acceptable model for the study of both corticosteroidsensitive and-resistant extraneuronal mechanisms, whereas the isolated adventitia is characterized by the presence of neuronal and extraneuronal mechanisms. © 1981 Springer-Verlag.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 6