[Neuropeptide Y contribution and the physiology of human sympathetic co-transmission. Studies in saphenous vein biopsies]. / Contribución del neuropéptido y a la fisiología de la co-transmisión simpática humana. Estudios en biopsias de vena safena.
Rev Med Chil
; 128(8): 829-38, 2000 Aug.
Article
em Es
| MEDLINE
| ID: mdl-11129543
BACKGROUND: It is known that the sympathetic varicosities co-store and co-release norepinephrine (NE) together with adenosine S-triphosphate (ATP) and neuropeptide Y (NPY). AIM: To describe the chemical characterization of stored and released NPY from the varicosities of sympathetic nerve terminals surrounding segments of the human saphenous vein, and the vasomotor activity of rings electrically depolarized or contracted by the exogenous application of the co-transmitters. MATERIAL AND METHODS: Saphenous vein tissues were obtained from patients undergoing elective cardiac revascularization surgery. RESULTS: The chromatographic profile of NPY extracted from biopsies is identical to a chemical standard of human NPY. Upon electrical depolarisation of the perivascular sympathetic nerve terminals, we demonstrated the release of NPY to the superfusion media, which did not exceed a 1% of its stored content. The release of the peptide is sensitive to guanethidine, and to extracellular calcium, suggesting that the mechanism of its release is exocytotic in nature. The electrically evoked release of NPY is dependent on the frequency and duration of the electrical pulses. Phenoxybenzamine reduces the electrically evoked release of NPY. Exogenous application of NE and ATP contract saphenous vein rings; the simultaneous application of NE plus ATP causes a synergic response, effect which is further potentiated by the joint co-application of 10 nM NPY. CONCLUSIONS: Present results highlight the role of NPY as a sympathetic co-transmitter in the regulation of human vascular tone.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Veia Safena
/
Neuropeptídeo Y
/
Trifosfato de Adenosina
/
Transmissão Sináptica
Limite:
Humans
Idioma:
Es
Revista:
Rev Med Chil
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Chile
País de publicação:
Chile