IBIMOL   23987
INSTITUTO DE BIOQUIMICA Y MEDICINA MOLECULAR PROFESOR ALBERTO BOVERIS
Unidad Ejecutora - UE
artículos
Título:
THE LOW AFFINITY NEUROTENSIN RECEPTOR ANTAGONIST LEVOCABASTINE IMPAIRS BRAIN NITRIC OXIDE SYNTHESIS AND MITOCHONDRIAL FUNCTION BY INDEPENDENT MECHANISMS
Autor/es:
LORES-ARNAIZ, S; RODRÍGUEZ DE LORES ARNAIZ, G; GUTNISKY, A.; KARADAYIAN, A.G.
Revista:
JOURNAL OF NEUROCHEMISTRY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2017 vol. 143 p. 684 - 696
ISSN:
0022-3042
Resumen:
Neurotensin is known to inhibit neuronal Na+, K+ -ATPase, an effect that is rescued by nitric oxide (NO) synthase inhibition. However, whether the neurotensinergic and the nitrergic systems are independent pathways, or are mechanistically linked, is unknown. Here, we addressed this issue and found that the administration of NTS2 antagonist, levocabastine (50 μg/kg, i.p.) inhibited NO synthase (NOS) activity by 74 and 42% after 18 h in synaptosomal and mitochondrial fractions isolated from the Wistar rat cerebral cortex, respectively; these effects disappeared 36 h after levocabastine treatment. Intriguingly, whereas neuronal NOS (nNOS) protein abundance decreased (by 56%) in synaptosomes membranes, it was enhanced (by 86%) in mitochondria 18 h after levocabastine administration. Levocabastine enhanced the respiratory rate of synaptosomes in the presence of oligomycin, but it failed to alter the spare respiratory capacity; furthermore, the mitochondrial respiratory chain (MRC) complexes I-IV activities were severely diminished by levocabastine administration. The inhibition of NOS and MRC complexes activities were also observed after incubation of synaptosomes and mitochondria with levocabastine (1 μM) in vitro. These data indicate that the NTS2 antagonist levocabastine regulates NOS expression and activity at the synapse, suggesting an interrelationship between the neurotensinergic and the nitrergic systems. However, the bioenergetics effects of NTS2 activity inhibition are likely to be independent from the regulation of NO synthesis.