| Texto completo | |
| Autor(es): |
Zatz, Roberto
;
De Nucci, Gilberto
Número total de Autores: 2
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PHYSIOLOGY; v. 39, n. 1, p. 16-pg., 2024-01-24. |
| Resumo | |
The review deals with the release of endothelium-derived dopamine and 6-nitrodopamine (6-ND) and its effects on isolated vascular tissues and isolated hearts. Basal release of both dopamine and 6-ND is present in human isolated umbilical cord vessels, human popliteal vessels, nonhuman primate vessels, and reptilia aortas. The 6-ND basal release was significantly reduced when the tissues were treated with N-omega-nitro-l-arginine methyl ester and virtually abolished when the endothelium was mechanically removed. 6-Nitrodopamine is a potent vasodilator, and the mechanism of action responsible for this effect is the antagonism of dopamine D-2-like receptors. As a vasodilator, 6-ND constitutes a novel mechanism by which nitric oxide modulates vascular tone. The basal release of 6-ND was substantially decreased in endothelial nitric oxide synthase knockout (eNOS(-/-)) mice and not altered in neuronal nitric oxide synthase knockout (nNOS(-/-)) mice, indicating a nonneurogenic source for 6-ND in the heart. Indeed, in rat isolated right atrium, the release of 6-ND was not affected when the atria were treated with tetrodotoxin. In the rat isolated right atrium, 6-ND is the most potent endogenous positive chronotropic agent, and in Langendorff's heart preparation, it is the most potent endogenous positive inotropic agent. The positive chronotropic and inotropic effects of 6-ND are antagonized by beta(1)-adrenoceptor antagonists at concentrations that do not affect the effects induced by noradrenaline, adrenaline, and dopamine, indicating that blockade of the 6-ND receptor is the major modulator of heart chronotropism and inotropism. The review proposes that endothelium-derived catecholamines may constitute a major mechanism for control of vascular tone and heart functions, in contrast to the overrated role attributed to the autonomic nervous system. (AU) | |
| Processo FAPESP: | 23/01376-6 - Avaliação das ações da 6-Nitrodopamina sobre a função renal e geniturinária |
| Beneficiário: | Roberto Zatz |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |
| Processo FAPESP: | 19/16805-4 - Avaliação do papel fisiopatológico das catecolaminas endoteliais |
| Beneficiário: | Gilberto de Nucci |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |