Comparison of Electrical Properties of Middle Cerebral and Mesenteric Artery in Cat
Document Type
Article
Publication Date
1-1-1980
Description
Some electrophysiological properties of the smooth muscle within the middle cerebral artery of the cat were recorded with glass microelectrodes and compared to those of mesenteric and coronary arteries of the same animal. The results demonstrated a significantly higher resting membrane potential (E(m)) in the middle cerebral arteries (-70 mV) when compared to the mesenteric (-49 mV) and coronary (-58 mV) arteries. When the E(m) was measured at different values of extracellular potassium, the middle cerebral artery depolarized with a maximum slope of 58 mV/decade vs. 36 mV/decade in the mesenteric arteries. The input resistance was less (6 MΩ) in the middle cerebral artery than in the mesenteric artery (10 MΩ), suggesting that potassium conductance (G(K)) is higher in the middle cerebral artery depolarized by 20 mV vs. 8 mV in the mesenteric artery. Such data suggest that both an elevated G(K) and greater electrogenic Na-K pump may contribute to the steeper slope of the E(m) vs. log[K](o) curve in the middle cerebral artery compared to the mesenteric artery. Spontaneous electrical activity was recorded in the middle cerebral artery upon depolarization with potassium, but only graded depolarizations were recorded in the mesenteric artery. Serotonin (10-6 M) depolarized the smooth muscle of the middle cerebral arteries and produced spontaneous electrical activity, which could be blocked by verapamil. The results of this study demonstrate marked differences in the electrical properties of the smooth muscle cells of the middle cerebral artery compared to the mesenteric artery.
Citation Information
Harder, D. R.. 1980. Comparison of Electrical Properties of Middle Cerebral and Mesenteric Artery in Cat. American Journal of Physiology - Cell Physiology. Vol.8(1). https://doi.org/10.1152/ajpcell.1980.239.1.c23 PMID: 7395983 ISSN: 0363-6143