id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-016742-y7jgjera	Bauer, Maria	Cardiovascular Anatomy and Pharmacology	2017-07-03		.txt	text/plain	23159	1335	40	The binding of an agonist to the adrenergic receptor replaces guanosine diphosphate (GDP) by guanosine triphosphate (GTP), and causes the α-subunit of the G-protein to break free from the β-γ complex, and act as a primary messenger: in beta receptors, it stimulates adenylate cyclase and triggers cyclic adenosine monophosphate (cAMP) production, which, as a second messenger in the process of signal transduction, activates its target kinases that phosphorylate regulator proteins and ultimately increases intracellular calcium levels. Their main anti-ischemic effects are due to their ability to reduce myocardial O 2 consumption by depressing contractility, decreasing heart rate and systemic afterload, and increasing O 2 supply by coronary and collateral vasodilation. Verapamil decreases the heart rate by depressing sinoatrial and AV-nodal activity (hence its utility in the treatment of supraventricular arrhythmias), lowers systemic blood pressure due to myocardial depression and peripheral vasodilation, and produces moderate coronary artery dilation (preferred in essential hypertension and vasospastic angina).	./cache/cord-016742-y7jgjera.txt	./txt/cord-016742-y7jgjera.txt