The BK potassium channel in the vascular smooth muscle and kidney: α- and β-subunits

Roland S Wu1, Steven O Marx

  • 1Division of Cardiology, Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York, USA. roland.wu@gmail.com

Kidney International
|September 24, 2010
PubMed

Related Concept Videos

Adrenergic Receptors: β Subtype01:26

Adrenergic Receptors: β Subtype

β-adrenoceptors have varied sensitivities towards adrenaline, noradrenaline, and isoprenaline. The order of agonist potency is as follows:
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors have equal affinities for...
Antihypertensive Drugs: Action of β1 Blockers01:17

Antihypertensive Drugs: Action of β1 Blockers

β1-receptors are primarily located in the heart and kidneys. In cardiac myocytes, these receptors interact with neurotransmitters released by the sympathetic nervous system during heightened activity or danger. As a result, β1-receptors get activated, initiating a series of biochemical processes. Excessive activation of beta receptors due to chronic stress can abnormally increase heart rate and contractility, resulting in high blood pressure or hypertension. To counteract this, β1-blockers...
Antihypertensive Drugs: Action of Calcium Channel Blockers01:18

Antihypertensive Drugs: Action of Calcium Channel Blockers

Calcium ions are essential to contract smooth muscle cells in blood vessels. They enter these cells through voltage-dependent calcium channels, specifically L-type calcium channels in the cell membrane. These L-type calcium channels are integral to the excitation-contraction coupling process in smooth muscle. When a stimulus is received by smooth muscle cells, their membrane depolarizes. This alteration in membrane potential instigates the opening of L-type calcium channels. As a result,...
Adrenergic Receptors: ɑ Subtype01:31

Adrenergic Receptors: ɑ Subtype

Adrenoceptors are classified into α and ꞵ classes based on their potencies to catecholamine agonists. α-adrenoceptors show the following order of catecholamine potency:
Adrenaline ≥ Noradrenaline >> Isoprenaline
α-adrenoceptors are further divided into α1 and α2-adrenoceptors.
α1-Adrenoceptors: These receptors are located postsynaptically on the effector organs and cause constriction of smooth muscle mediated by activation of phospholipase C—inositol-1,4,5-trisphosphate...
Adrenergic Antagonists: Chemistry and Classification of β-Receptor Blockers01:25

Adrenergic Antagonists: Chemistry and Classification of β-Receptor Blockers

β-adrenergic antagonists, or β-blockers, modulate the sympathetic nervous system by targeting β-adrenoceptors and inhibiting catecholamine-mediated sympathetic responses. β-blockers differ in their adrenoceptor subtype affinity, lipophilicity, and α-blocking capabilities. The history of β-blocker development began with the prototype, dichloroisoprenaline, which exhibited partial agonist activity. As a result, propranolol was developed as a pure antagonist but nonselective agent, paving the way...
Antihypertensive Drugs: Types of β-Blockers01:28

Antihypertensive Drugs: Types of β-Blockers

β receptors are classified into three subclasses: β1, β2, and β3. β1 receptors are primarily located in the heart and kidneys. When they get activated, they increase heart rate, contractility, and renin release. This process enhances blood pressure and aids in stress management. In contrast, β2 receptors are situated mainly in the lungs, blood vessels, and skeletal muscles. Upon activation, they trigger smooth muscle relaxation, causing bronchodilation and vasodilation. This widens airways and...