Calcium and Sodium Channels in Spontaneously Contracting Vascular Muscle Cells

Electrophysiological recordings of inward currents from whole cells showed that vascular muscle cells have one type of sodium channel and two types of calcium channels. One of the calcium channels, the transient calcium channel, was activated by small depolarizations but then rapidly inactivated. It...

Full description

Saved in:
Bibliographic Details
Published in:Science (American Association for the Advancement of Science) 1986-07, Vol.233 (4762), p.475-478
Main Authors: Sturek, Michael, Hermsmeyer, Kent
Format: Article
Language:English
Subjects:
Animals
Biochemistry
Biological and medical sciences
Blood vessels and receptors
Cadmium
Calcium
Calcium - physiology
Calcium channels
cardiac muscle
Cell lines
Cell membranes
Depolarization
Electric current
Electric potential
Electrophysiology
Fundamental and applied biological sciences. Psychology
Ion Channels - physiology
Medical research
Membrane Potentials
Muscle cells
Muscle Contraction
Muscle, Smooth, Vascular - physiology
Muscular system
Rats
Rats, Inbred WKY
sodium
Sodium - physiology
Sodium channels
Vertebrates: cardiovascular system
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Electrophysiological recordings of inward currents from whole cells showed that vascular muscle cells have one type of sodium channel and two types of calcium channels. One of the calcium channels, the transient calcium channel, was activated by small depolarizations but then rapidly inactivated. It was equally permeable to calcium and barium and was blocked by cadmium, but not by tetrodotoxin. The other type, the sustained calcium channel, was activated by larger depolarizations, but inactivated very little; it was more permeable to barium than calcium. The sustained calcium channel was more sensitive to block by cadmium than the transient channel, but also was not blocked by tetrodotoxin. The sodium channel inactivated 15 times more rapidly than the transient calcium channel and at more negative voltages. This sodium channel, which is unusual because it is only blocked by a very high (60 $\mu $M) tetrodotoxin concentration but not by cadmium, is the first to be characterized in vascular muscle, and together with the two calcium channels, provides a basis for different patterns of excitation in vascular muscles.
ISSN:0036-8075
1095-9203
DOI:10.1126/science.2425434