Nicotine receptors

Several cholinergic strategies, other than cholinesterase inhibition, have been employed with the intention of ameliora ting the symptoms of AD. These include precursor loading acetylcholine release enhancement, and direct activation of both muscarinic and nicotinic receptors. 

Nicotinic Receptor Agonists. There has been significant activity in the development of muscarinic cholinergic receptor agonists for dementia. In addition, agents that interact with nicotinic cholinergic receptors may also have therapeutic value. Nicotinic receptors have been reported to be... 

Ganglionic blocking agent. A drug that blocks neurotransmission at the nicotinic receptors of the sympathetic ganglia, thus blocking vascular reflexes. 

Thermodynamically it would be expected that a ligand may not have identical affinity for both receptor conformations. This was an assumption in early formulations of conformational selection. For example, differential affinity for protein conformations was proposed for oxygen binding to hemoglobin [17] and for choline derivatives and nicotinic receptors [18]. Furthermore, assume that these conformations exist in an equilibrium defined by an allosteric constant L (defined as [Ra]/[R-i]) and that a ligand [A] has affinity for both conformations defined by equilibrium association constants Ka and aKa, respectively, for the inactive and active states ... 

Synaptic Transmission Voltage-dependent Na+ Channels Voltage dependent Ca2+ Channels Nicotinic Receptors... 

Nicotinic Receptors Voltage-dependent Na+ Channels Non-selective Cation Channels... 

Voltage-dependent Na+ Channels Nicotinic Receptors Ionotropic Glutamate Receptors Voltage-gated K+ Channels Inward Rectifier K+ Channels... 

GABAergic System Glycine Receptors Ionotropic Glutamate Receptors Nicotinic Receptors Local Anaesthetics... 

Transmembrane Signaling Nicotinic Receptors Purinergic System... 

Ionotropic Glutamate Receptors Nicotinic Receptors Non-selective Cation Channels K+ Channels... 

The neurotransmitter acetylcholine (ACh) exerts its diverse pharmacological actions via binding to and subsequent activation of two general classes of cell surface receptors, the nicotinic and the mAChRs. These two classes of ACh receptors have distinct structural and functional properties. The nicotinic receptors,... 

Nicotinic receptors (nicotinic acetylcholine receptors, nACHR) exist not only in the membrane of vertebrate skeletal muscle at the synapse between nerve and muscle (muscle-type nAChR) but also at various synapses throughout the brain, mainly at presynaptic positions (neuronal-type nAChR). Whereas the muscle-type nAChR is precisely composed of two a 1-subunits, one (3 -subunit, one y -subunit and one y -subunit (adult)... 

Nicotinic Receptors Muscle Relaxants Synaptic Transmission... 

The nicotinic receptor (nAChR) comprises a family of receptor subtypes that respond to the neurotransmitter acetylcholine (ACh) and the tobacco alkaloid nicotine. 

Nicotinic Receptors. Table 1 Some drugs that act at nAChRs... 

The open channel has in most cases a selective permeability, allowing a restricted class of ions to flow,for example Na+, K+, Ca++ or Cl- and, accordingly, these channels are called Na+-channels, K+-channels, Ca -channels and Cr-channels. In contrast, cation-permeable channels with little selectivity reject all anions but discriminate little among small cations. Little is known about the structures and functions of these non-selective cation channels [1], and so far only one of them, the nicotinic acetylcholine receptor (nAChR, see Nicotinic Receptors), has been characterized in depth [2, 3]. The nAChR is a ligand-gated channel (see below) that does not select well among cations the channel is even permeable to choline, glycine ethylester and tris buffer cations. A number of other plasma... 

Corringer P-J, LeNovere N, Changeux J-P (2000) Nicotinic receptors at the amino acid level. Annu Rev Pharmacol Toxicol 40 431-458... 

Ligand-induced signal transduction processes that are mediated by a ligand-operated ion channel, e.g., by the nicotinic receptor in muscle, result in an almost... 

Nicotinic Acetylcholine Receptor Nicotinic Receptors Nigrostriatal Tract/Pathway Nitrates... 

The nicotinic acetylcholine (nACh) receptor also displays sensitivity to inhalants (Bale et al. 2002). To varying degrees, toluene appeared to antagonize the function of nACh receptors that comprise different subunits. At concentrations of 50 pM to 10 mM, toluene produced a reversible, concentration-dependent inhibition of acetylcholine-induced current in Xenopus oocytes expressing various nicotinic receptor subtypes, with the ol — 2 d ct3—P2 subunit combinations being more sensitive to inhibition than other receptor... 

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