Adrenergic agonists Flashcards
What G-protein is alpha-1 receptor coupled to, and what signaling pathway does it activate?
The alpha-1 receptor is coupled to a Gq protein, which activates the IP3-DAG cascade, increasing intracellular calcium in smooth muscle cells.
What is the overall effect of alpha-1 receptor activation on peripheral arterial resistance?
Alpha-1 receptor activation increases peripheral arterial resistance by causing vasoconstriction in small arteries, and arterioles.
How does alpha-1 receptor activation influence venous return?
Alpha-1 receptor activation increases venous return by causing venoconstriction.
What effect does alpha-1 receptor activation have on mean arterial pressure?
Alpha-1 receptor activation increases mean arterial pressure through vasoconstriction.
alpha-1 receptor activation will occur where in the capillary bed?
precapillary sphincters.
How does alpha-1 receptor activation increase mean arterial pressure?
Alpha-1 receptor activation increases MAP by causing vasoconstriction in arteries and arterioles.
What effect does alpha-1 receptor activation have on the pupillary dilator muscle?
Alpha-1 receptor activation at the pupillary dilator muscle causes mydriasis, or pupillary dilation.
How does alpha-1 receptor activation affect the urethral sphincter and prostatic smooth muscle?
Alpha-1 receptor activation causes contraction of the urethral sphincter and prostatic smooth muscle.
What is the effect of alpha-1 receptor activation on urinary retention?
Alpha-1 receptor activation leads to urinary retention due to smooth muscle contraction.
What G-protein is alpha-2 receptor coupled to, and how does it affect cyclic AMP?
The alpha-2 receptor is coupled to a Gi protein, which decreases cyclic AMP levels.
What is the mechanism by which alpha-2 receptor activation reduces sympathetic tone?
Alpha-2 receptor activation reduces sympathetic tone by decreasing cyclic AMP levels in presynaptic neurons.
What is the primary central effect of alpha-2 agonists?
Alpha-2 agonists act centrally to reduce sympathetic tone, functioning as sympatholytics.
How does alpha-2 receptor activation at presynaptic terminals affect neurotransmitter release?
Alpha-2 receptor activation inhibits neurotransmitter release at presynaptic terminals.
What effect does alpha-2 activation have on insulin release from pancreatic islet cells?
Alpha-2 receptor activation decreases insulin release from pancreatic islet cells.
How does alpha-2 receptor activation affect lipolysis?
Alpha-2 receptor activation inhibits lipolysis and the release of free fatty acids.
What is the role of alpha-2 receptor activation in the ciliary body?
Alpha-2 receptor activation at the ciliary body reduces aqueous humor production.
What is a clinical use of brimonidine, an alpha-2 agonist?
Brimonidine, an alpha-2 agonist, is used to treat chronic open-angle glaucoma by decreasing aqueous humor production.
What G-protein is beta-1 receptor coupled to, and how does it affect cyclic AMP?
The beta-1 receptor is coupled to a Gs protein, which increases cyclic AMP levels.
What is the effect of beta-1 receptor activation on cardiac myocytes?
Beta-1 receptor activation increases cardiac contractility by increasing intracellular calcium in cardiac myocytes. Activation results in increased cardiac output.
What is the effect of beta-1 receptor activation on cardiac contractility and renin release?
Beta-1 receptor activation increases cardiac contractility and renin release, enhancing cardiac output and blood volume regulation.
How does beta-1 receptor activation influence heart rate?
Beta-1 receptor activation increases heart rate by enhancing activity at the sinoatrial node.
What is the effect of beta-1 receptor activation on renin release?
Beta-1 receptor activation increases renin release from juxtaglomerular apparatus cells.
What G-protein is beta-2 receptor coupled to, and what signaling pathway does it activate?
The beta-2 receptor is coupled to a Gs protein, which increases cyclic AMP and activates protein kinase A.
How does beta-2 receptor activation affect bronchial smooth muscle?
Beta-2 receptor activation causes bronchodilation by relaxing bronchial smooth muscle.