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Sponsored by APS Cardiovascular Section Ion Channels |
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Tuesday, May 1 — 10:30 AM-12:30 PM Washington, DC Convention Center — Room 145A |
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| Chaired: |
Robert M. Bryan, Jr., Baylor Col. of
Med. |
Potassium (K) channels in vascular smooth muscle and endothelium are important regulators of vascular function including the control of vessel tone. Until recently the K channels studied in vascular cells have been members of either the inwardly rectifying K channel family or the voltage/Ca –gated K channel family. Members of the inwardly rectifying K channel family include inwardly rectifying (Kir) and the ATP-sensitive (KATP) K channels. Members of the voltage/Ca –gated K channel family include Ca-activated (KCa) and voltage sensitive or delayed rectifier (Kv) K channels. In the last 10 years, a third family of K channels, 2P domain K channels (K2P), has been discovered and cloned. This family of channels is distinct in that each protein subunit has two pore or P domains unlike channels in the other two families which have only one P domain for each subunit. Currently, we now recognize that there are at least 12 genes coding for functional K2P channels. Depending on the individual family member, K2P can be regulated by one or more of the following: pH, temperature, mechanical perturbation, anesthetics, arachidonic acid and other poly-unsaturated fatty acids, DAG, PIP2, phospholipids, G proteins, PKG, PKC, PKA, and casein kinase.
K2P are found in virtually all tissues and organs throughout the body and are being shown to have important roles in the regulation of physiological processes. While message and/or protein for most of the K2P channels have been reported in blood vessels, we are only beginning to demonstrate their role in regulating vascular function. Given the diversity of expression in vessels and the importance already demonstrated, the recognition of K2P channels as major regulators of function will certainly grow.
This symposium will bring together researchers who have studied vascular K2P channels in a single forum with the purpose of (1) introducing this newly discovered class of K channels to biologists (2) demonstrating that 2P domain K channels have a major role in controlling vascular function, and (3) demonstrating potential new targets for therapeutic intervention during pathological states. In this symposium, Michel Lazdunski will give an overview of the K2P channels and discuss a neuroprotective role for K2P channels following stroke and seizure. Alison Gurney will discuss the role of K2P channels in setting the resting membrane potential in pulmonary arteries and their involvement during hypoxic conditions. Gillian Edwards will highlight the widespread distribution of K2P channels in vascular myocytes and endothelial cells. She will show how extracellular pH changes, together with pharmacological and siRNA approaches can be used to investigate the importance of these channels not only in blood vessels, but also in the airways and urinary bladder. Robert Bryan will discuss a role for K2P channels in dilations of cerebral arteries. This symposium brings together the major scientists who are presently investigating the critical importance of K2P in the circulation and other systems. The symposium will update anyone interested in vascular smooth muscle, vascular control, and/or novel K channels.
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10:30 AM |
2P K channels: an overview and their role in
neuroprotection. |
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11:05 AM |
The regulation of pulmonary artery tone by 2P K
channels. |
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11:30 AM |
Effects of pH and pharmacological modulation on
vascular tone: a role for 2P K channels. |
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11:55 PM |
Cerebral artery dilations by 2P K channels. |