Membrane Electrical Mechanism of Basilar Artery Constriction and Pial Artery Dilation by Norepinephrine
Document Type
Article
Publication Date
1-1-1981
Description
To study the mechanism by which norepinephrine acts on vascular muscle cell membrane, the authors recorded membrane potential with intracellular microelectrodes in isolated cat basilar and pial arteries. On addition of norepinephrine concentrations less than 1 μM, pial arteries hyperpolarized and relaxed while basilar arteries depolarized and contracted. Relaxation and hyperpolarization of the pial arteries occurred without the need for addition of any other drug, which indicates the relaxation of spontaneous tone. The relaxation and hyperpolarization could be completely blocked by addition of propranolol before exposure to norepinephrine. The depolarization and contraction of both basilar and pial arteries was blocked by the previous exposure to phentolamine. Electrical spikes were not found spontaneously, but could be induced in both arteries by tetraethylammonium and subsequent addition of norepinephrine, blockable by phentolamine. The authors concluded the membrane property differences between basilar and pial arteries result in qualitatively different effects of norepinephrine.
Citation Information
Harder, D. R.; Abel, P. W.; and Hermsmeyer, K.. 1981. Membrane Electrical Mechanism of Basilar Artery Constriction and Pial Artery Dilation by Norepinephrine. Circulation Research. Vol.49(6). 1237-1242. https://doi.org/10.1161/01.RES.49.6.1237 PMID: 7307242 ISSN: 0009-7330