Endogenous nitric oxide modulates sympathetic neuroeffector transmission in the isolated rabbit lateral saphenous vein

Gordon, J.F., Baird, M., Daly, C.J. and McGrath, J.C. (1992) Endogenous nitric oxide modulates sympathetic neuroeffector transmission in the isolated rabbit lateral saphenous vein. Journal of Cardiovascular Pharmacology, 20(Sup 12), S68-S71.

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Abstract

The rabbit isolated lateral saphenous vein (RLSV) has a heterogeneous population of alpha-adrenoceptors. Responses to electrical field stimulation, in the presence of cocaine, exhibit both alpha 1- and alpha 2-adrenoceptor-mediated components. The present study examined sympathetic neuroeffector transmission and the response to exogenous catecholamines after inhibition of nitric oxide (NO) synthesis with N omega-nitro-L-arginine methyl ester (L-NAME). A comparison of the response in the presence and absence of a functional endothelium was also carried out. L-NAME potentiated the first and second components of the response to nerve stimulation on the order of 300 and 500%, respectively. L-NAME also significantly potentiated responses to norepinephrine (NE), phenylephrine (PE), and UK 14304. Selective antagonism of the first phase was seen with prazosin (alpha 1-antagonist, 0.1 microM) and the second phase with rauwolscine (alpha 2-antagonist, 1 microM). In the presence of L-NAME, the remaining (uninhibited) components were potentiated. Removal of endothelial function induced by gentle rubbing of the intimal surface abolished potentiation to exogenous NE, PE, and UK14304 by L-NAME. However, a significant degree of potentiation of the neurogenic response was observed in the rubbed tissues in response to L-NAME. This suggests that there may be a nonendothelial source of NO that can modulate the neurogenic response to electrical field stimulation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:McGrath, Professor John and Daly, Dr Craig
Authors: Gordon, J.F., Baird, M., Daly, C.J., and McGrath, J.C.
College/School:College of Medical Veterinary and Life Sciences > School of Life Sciences
Journal Name:Journal of Cardiovascular Pharmacology
Publisher:Lippincott Williams & Wilkins
ISSN:0160-2446
ISSN (Online):1533-4023

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