Biomaterial Database

Modulation by nicotine on binding of cerebral muscarinic receptors with muscarinic agonist and antagonist. 1996

H Wang, and W Y Cui, and C H Liu

Institute of Pharmacology and Toxicology, Beijing, China.

OBJECTIVE To study the modulatory effects of nicotine on the binding of brain muscarinic receptors. METHODS The binding of brain muscarinic receptors with the agonist [3H] oxotremorine-M or the antagonist l-[3H]QNB was determined in the presence/absence of nicotine. RESULTS Pre-incubation of the membrane fraction derived from rat cerebral cortex with nicotine 1.0 mumol.L-1 led to a decrease in the dissociation constant (Kd) for [3H] oxotremorine-M binding to muscarinic receptors, while the maximal binding value (Bmax) was unchanged. The Kd value for binding of the muscarinic antagonist l-[3H]QNB was concentration-dependently increased by preincubation with nicotine 0.1 nmol.L-1-10.0 mumol.L-1, with Bmax unchanged. The effect of nicotine on the Kd for l-[3H]QNB binding was prevented by mecamylamine 10 nmol.L-1, but was enhanced by dithiothreitol 10 mumol.L-1, which by itself was also capable of increasing the Kd value. CONCLUSIONS Nicotine increases the affinity of brain muscarinic receptors for muscarinic agonist, but decreases the affinity of brain muscarinic receptors for muscarinic antagonist.

UI	MeSH Term	Description	Entries
D009538	Nicotine	Nicotine is highly toxic alkaloid. It is the prototypical agonist at nicotinic cholinergic receptors where it dramatically stimulates neurons and ultimately blocks synaptic transmission. Nicotine is also important medically because of its presence in tobacco smoke.	Nicotine Bitartrate,Nicotine Tartrate
D010095	Oxotremorine	A non-hydrolyzed muscarinic agonist used as a research tool.	Oxytremorine
D011813	Quinuclidinyl Benzilate	A high-affinity muscarinic antagonist commonly used as a tool in animal and tissue studies.	Benzilate, Quinuclidinyl
D011976	Receptors, Muscarinic	One of the two major classes of cholinergic receptors. Muscarinic receptors were originally defined by their preference for MUSCARINE over NICOTINE. There are several subtypes (usually M1, M2, M3....) that are characterized by their cellular actions, pharmacology, and molecular biology.	Muscarinic Acetylcholine Receptors,Muscarinic Receptors,Muscarinic Acetylcholine Receptor,Muscarinic Receptor,Acetylcholine Receptor, Muscarinic,Acetylcholine Receptors, Muscarinic,Receptor, Muscarinic,Receptor, Muscarinic Acetylcholine,Receptors, Muscarinic Acetylcholine
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus
D018721	Muscarinic Agonists	Drugs that bind to and activate muscarinic cholinergic receptors (RECEPTORS, MUSCARINIC). Muscarinic agonists are most commonly used when it is desirable to increase smooth muscle tone, especially in the GI tract, urinary bladder and the eye. They may also be used to reduce heart rate.	Cholinergic Agonists, Muscarinic,Cholinergic Agonist, Muscarinic,Cholinergic Muscarinic Agonists,Muscarinic Agonist,Agonist, Muscarinic,Agonist, Muscarinic Cholinergic,Agonists, Cholinergic Muscarinic,Agonists, Muscarinic,Agonists, Muscarinic Cholinergic,Muscarinic Agonists, Cholinergic,Muscarinic Cholinergic Agonist,Muscarinic Cholinergic Agonists
D018722	Nicotinic Agonists	Drugs that bind to and activate nicotinic cholinergic receptors (RECEPTORS, NICOTINIC). Nicotinic agonists act at postganglionic nicotinic receptors, at neuroeffector junctions in the peripheral nervous system, and at nicotinic receptors in the central nervous system. Agents that function as neuromuscular depolarizing blocking agents are included here because they activate nicotinic receptors, although they are used clinically to block nicotinic transmission.	Cholinergic Agonists, Nicotinic,Cholinergic Agonist, Nicotinic,Nicotinic Agonist,Agonist, Nicotinic,Agonist, Nicotinic Cholinergic,Agonists, Nicotinic,Agonists, Nicotinic Cholinergic,Nicotinic Cholinergic Agonist,Nicotinic Cholinergic Agonists
D018727	Muscarinic Antagonists	Drugs that bind to but do not activate MUSCARINIC RECEPTORS, thereby blocking the actions of endogenous ACETYLCHOLINE or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system.	Antimuscarinic,Antimuscarinic Agent,Antimuscarinic Agents,Cholinergic Muscarinic Antagonist,Muscarinic Antagonist,Antimuscarinics,Cholinergic Muscarinic Antagonists,Agent, Antimuscarinic,Agents, Antimuscarinic,Antagonist, Cholinergic Muscarinic,Antagonist, Muscarinic,Antagonists, Cholinergic Muscarinic,Antagonists, Muscarinic,Muscarinic Antagonist, Cholinergic,Muscarinic Antagonists, Cholinergic