Search results
Results From The WOW.Com Content Network
The beta-2 adrenergic receptor (β 2 adrenoreceptor), also known as ADRB2, is a cell membrane-spanning beta-adrenergic receptor that binds epinephrine (adrenaline), a hormone and neurotransmitter whose signaling, via adenylate cyclase stimulation through trimeric G s proteins, increases cAMP, and, via downstream L-type calcium channel interaction, mediates physiologic responses such as smooth ...
Beta 2-adrenergic agonists, also known as adrenergic β 2 receptor agonists, are a class of drugs that act on the β 2 adrenergic receptor. Like other β adrenergic agonists , they cause smooth muscle relaxation. β 2 adrenergic agonists' effects on smooth muscle cause dilation of bronchial passages , vasodilation in muscle and liver ...
Activation of β 2 receptors induces smooth muscle relaxation in the lungs, gastrointestinal tract, uterus, and various blood vessels. Increased heart rate and heart muscle contraction are associated with the β1 receptors; however, β 2 cause vasodilation in the myocardium. [citation needed] β3 receptors are mainly located in adipose tissue. [5]
Vascular smooth muscle contracts or relaxes to change both the volume of blood vessels and the local blood pressure, a mechanism that is responsible for the redistribution of the blood within the body to areas where it is needed (i.e. areas with temporarily enhanced oxygen consumption).
Beta 2 blockers cease action of beta-2 receptor by blocking the receptor and preventing it from being activated. [6] Similar to beta-1 receptor, the activated beta-2 receptor will lead to the detach of alpha subunit of Gs protein and attachment of adenylate cyclase. [6] Adenosine triphosphate(ATP), is then catalyzed to form cAMP.
When NE is released into the synapse, it feeds back on the α 2 receptor, causing less NE release from the presynaptic neuron. This decreases the effect of NE. There are also α 2 receptors on the nerve terminal membrane of the post-synaptic adrenergic neuron. Actions of the α 2 receptor include: decreased insulin release from the pancreas [19]
β 2-adrenoceptor agonists are a group of drugs that act selectively on β 2-receptors in the lungs causing bronchodilation. β 2-agonists are used to treat asthma and COPD, diseases that cause obstruction in the airways. Prior to their discovery, the non-selective beta-agonist isoprenaline was used.
The Centers for Disease Control and Prevention estimate that 1 in 11 children and 1 in 12 adults have asthma in the United States of America. [1] According to the World Health Organization, asthma affects 235 million people worldwide. [2] There are two major categories of asthma: allergic and non-allergic.