Electrical activation of endothelium evokes vasodilation and hyperpolarization along hamster feed arteries
- 1 January 2001
- journal article
- research article
- Published by American Physiological Society in American Journal of Physiology-Heart and Circulatory Physiology
- Vol. 280 (1), H160-H167
- https://doi.org/10.1152/ajpheart.2001.280.1.h160
Abstract
Endothelial cells are considered electrically unexcitable. However, endothelium-dependent vasodilators (e.g., acetylcholine) often evoke hyperpolarization. We hypothesized that electrical stimulation of endothelial cells could evoke hyperpolarization and vasodilation. Feed artery segments (resting diameter: 63 ± 1 μm; length 3–4 mm) of the hamster retractor muscle were isolated and pressurized to 75 mmHg, and focal stimulation was performed via microelectrodes positioned across one end of the vessel. Stimulation at 16 Hz (30–50 V, 1-ms pulses, 5 s) evoked constriction (−20 ± 2 μm) that spread along the entire vessel via perivascular sympathetic nerves, as shown by inhibition with tetrodotoxin, ω-conotoxin, or phentolamine. In contrast, stimulation with direct current (30 V, 5 s) evoked vasodilation (16 ± 2 μm) and hyperpolarization (11 ± 1 mV) of endothelial and smooth muscle cells that conducted along the entire vessel. Conducted responses were insensitive to preceding treatments, atropine, orNω-nitro-l-arginine, yet were abolished by endothelial cell damage (with air). Injection of negative current (≤1.6 nA) into a single endothelial cell reproduced vasodilator responses along the entire vessel. We conclude that, independent of ligand-receptor interactions, endothelial cell hyperpolarization evokes vasodilation that is readily conducted along the vessel wall. Moreover, electrical events originating within a single endothelial cell can drive the relaxation of smooth muscle cells throughout the entire vessel.Keywords
This publication has 26 references indexed in Scilit:
- Heterogeneity of Vascular Innervation in Hamster Cheek Pouch and Retractor MuscleJournal of Vascular Research, 1999
- Spread of vasodilatation and vasoconstriction along feed arteries and arterioles of hamster skeletal muscleThe Journal of Physiology, 1999
- ION CHANNELS IN VASCULAR ENDOTHELIUMAnnual Review of Physiology, 1997
- Morphology Favors an Endothelial Cell Pathway for Longitudinal Conduction within ArteriolesMicrovascular Research, 1997
- Voltage‐dependent calcium entry in confluent bovine capillary endothelial cellsFEBS Letters, 1992
- Haemodynamic shear stress activates a K+ current in vascular endothelial cellsNature, 1988
- The contributions of noradrenaline and ATP to the responses of the rabbit central ear artery to sympathetic nerve stimulation depend on the parameters of stimulationEuropean Journal of Pharmacology, 1986
- Ultrastructural localization of choline acetyltransferase in vascular endothelial cells in rat brainNature, 1985
- Spread of contraction in rabbit ear artery preparations in response to stimulation by norepinephrine.Circulation Research, 1981
- Histologic study of living striated muscle fibers in situ in the cheek pouch of the golden hamsterJournal of Anatomy, 1958