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6-Nitrodopamine potentiates contractions of rat isolated vas deferens induced by noradrenaline, adrenaline, dopamine and electric field stimulation

Full text
Author(s):
Britto-Junior, Jose ; Lima, Antonio Tiago ; Campos, Rafael ; Giao, Alexandre Asturiano ; Mendes, Gustavo Duarte ; Silva, Luiza P. Ferreira-Novaes P. ; Fregonesi, Adriano ; Pupo, Andre Sampaio ; Antunes, Edson ; De Nucci, Gilberto
Total Authors: 10
Document type: Journal article
Source: NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY; v. N/A, p. 16-pg., 2023-04-04.
Abstract

6-Nitrodopamine (6-ND) is a novel endogenous catecholamine that is released from the rat isolated vas deferens, and has been characterized as a major modulator of the contractility of rat isolated epididymal vas deferens (RIEVD). Drugs such as tricyclic antidepressants, alpha(1) and beta(1)beta(2) adrenoceptor blockers, act as selective antagonists of the 6-ND receptor in the RIEVD. In the rat isolated atria, 6-ND has a potent positive chronotropic action and causes remarkable potentiation of the positive chronotropic effects induced by dopamine, noradrenaline, and adrenaline. Here, whether 6-ND interacts with the classical catecholamines in the rat isolated vas deferens was investigated. Incubation with 6-ND (0.1 and 1 nM; 30min) caused no contractions in the RIEVD but provoked significant leftward shifts in the concentration-response curves to noradrenaline, adrenaline, and dopamine. Pre-incubation of the RIEVD with 6-ND (1 nM), potentiated the contractions induced by electric-field stimulation (EFS), whereas pre-incubation with 1 nM of dopamine, noradrenaline or adrenaline, did not affect EFS-induced contractions. In tetrodotoxin (1 mu M) pre-treated (30 min) RIEVD, pre-incubation with 6-ND (0.1 nM) did not cause leftward shifts in the concentration-dependent contractions induced by noradrenaline, adrenaline, or dopamine. Pre-incubation of the RIEVD with the alpha(2A)-adrenoceptor antagonist idazoxan (30 min, 10 nM) did not affect dopamine, noradrenaline, adrenaline, and EFS-induced contractions. However, when idazoxan (10 nM) and 6-ND (0.1 nM) were simultaneously pre-incubated (30 min), a significant potentiation of the EFS-induced contractions of the RIEVD was observed. 6-nitrodopamine causes remarkable potentiation of dopamine, noradrenaline, and adrenaline contractions on the RIEVD, due to activation of adrenergic terminals, possibly via pre-synaptic adrenoceptors. (AU)

FAPESP's process: 21/14414-8 - Evaluation of the action of nitro-catecholamines in the cardiovascular system
Grantee:José Britto Júnior
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 17/15175-1 - Modulation of soluble guanylate cyclase and the intracellular levels of cyclic nucleotides in the lower urinary tract and prostate
Grantee:Edson Antunes
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 19/16805-4 - Evaluation of the pathophysiological role of endothelial catecholamines
Grantee:Gilberto de Nucci
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 22/08232-7 - Pharmacological characterization of 6-Nitrodopamine in the systemic and renal hemodynamics of mammals and reptiles
Grantee:Rafael de Morais Campos
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 22/06644-6 - Evaluation of 6-nitronoradrenaline in rat vas deferens
Grantee:Luiza Pires Ferreira Novaes da Silva
Support Opportunities: Scholarships in Brazil - Scientific Initiation
FAPESP's process: 21/13593-6 - Evaluation of chronic 6-nitrodopamine treatment in rats
Grantee:Antonio Tiago Silva Lima
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)