|
A ganglionic blocker (or ganglioplegic) is a type of medication that inhibits transmission between preganglionic and postganglionic neurons in the Autonomic Nervous System, often by acting as a nicotinic receptor antagonist. Nicotinic acetylcholine receptors are found on skeletal muscle, but also within the route of transmission for the parasympathetic and sympathetic nervous system (which together comprise the autonomic nervous system). More specifically, nicotinic receptors are found within the ganglia of the autonomic nervous system, allowing outgoing signals to be transmitted from the presynaptic to the postsynaptic cells. Thus, for example, blocking nicotinic acetylcholine receptors blocks both sympathetic (excitatory) and parasympathetic (calming) stimulation of the heart. The nicotinic antagonist hexamethonium,, for example, does this by blocking the transmission of outgoing signals across the autonomic ganglia at the postsynaptic nicotinic acetylcholine receptor. Because ganglionic blockers block both the parasympathetic nervous system and sympathetic nervous system, the effect of these drugs depends upon the dominant tone in the organ system. ==Examples== The first ganglion-blocker to be used clinically was tetraethylammonium, although it was soon superseded by better drugs.〔''Drill's Pharmacology in Medicine, 4th Ed.'' (1971). J. R. DiPalma (Ed.), pp. 723-724, New York: McGraw-Hill.〕 Nicotinic receptor antagonists: * hexamethonium * pentolinium * mecamylamine * trimetaphan * tubocurarine * pempidine * benzohexonium * chlorisondamine * pentamine Nicotinic receptor agonists (acting through depolarization block): * nicotine Blocking ACh release in autonomic ganglia (although these have many other actions elsewhere): * botulinum toxin 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「ganglionic blocker」の詳細全文を読む スポンサード リンク
|