Related Experiment Video
Updated: Aug 18, 2026

Mesenteric Artery Contraction and Relaxation Studies Using Automated Wire Myography
Published on: September 22, 2011
Functional role of Ca(2+)-activated K+ channels in resting state of carotid arteries from SHR
M Asano1, K Masuzawa-Ito, T Matsuda
1Department of Pharmacology, Nagoya City University Medical School, Japan.
Abstract:
Carotid arteries from spontaneously hypertensive rats (SHR) exhibited an active tone when exposed to a physiological salt solution; that is, the tension decreased when nifedipine was added. To determine the possible role of Ca(2+)-activated K+ (KCa) channels in the resting state of these arteries, the effects of agents that interact with these channels on tension and 86Rb efflux were compared in endothelium-denuded strips of carotid arteries from SHR and normotensive Wistar-Kyoto rats (WKY). The addition of charybdotoxin, a blocker of high-conductance KCa channels, to the resting strips produced a concentration-dependent contraction in SHR but not in WKY. In resting strips preloaded with 86Rb, the basal 86Rb efflux rate constant was significantly greater in SHR than in WKY. The addition of nifedipine to the resting strips decreased the basal 86Rb efflux rate constant only in SHR. The effect of nifedipine on tension and 86Rb efflux in 25.9 mM K(+)-contracted strips of WKY was comparable to the effect of this blocker in the resting strips of SHR. The basal 45Ca influx in resting strips of SHR was significantly increased when compared with WKY, and this increase in SHR was abolished by nifedipine. These results suggest that the transmembrane Ca2+ influx via L-type voltage-dependent Ca2+ channels was significantly increased in the resting state of carotid arteries from SHR and that the KCa channels were highly activated.
More Related Videos
11:02Exploring Arterial Smooth Muscle Kv7 Potassium Channel Function using Patch Clamp Electrophysiology and Pressure Myography
Published on: September 14, 2012
07:19Recording of Inward Rectifying K+ Currents in Freshly Isolated Basilar Artery Smooth Muscle Cells by Patch Clamp Technique
Published on: February 7, 2025
Related Concept Videos
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
G-Protein Gated Ion Channels
Sensory organs,...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Nitric Oxide Signaling Pathway
Smooth Muscle Contraction
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...
Antihypertensive Drugs: Action of Calcium Channel Blockers