Ibogaine noncompetitively blocked (IC50 approximately 20 nM) 22NaCl influx through ganglionic-type nicotinic receptor channels of rat pheochromocytoma PC12 cells. The major metabolite O-des-methylibogaine was 75-fold less active, and O-t-butyl-O-des-methylibogaine was 20-fold less active. Ibogaine was relatively weak as a blocker (IC50 approximately 2000 nM) of the neuromuscular-type nicotinic ...

Synaptic modulation and long-term synaptic changes are thought to be the cellular correlates for learning and memory (Madison et al., 1991; Aiba et al., 1994, Goda and Stevens, 1996). The hippocampus is a center for learning and memory that receives abundant cholinergic innervation and has a high density of nicotinic acetylcholine receptors (nAChRs) (Wada et al., 1989; Woolf, 1991). We report t...

We report a liquid-chromatographic procedure for determining free nicotinic acid and a metabolite, nicotinuric acid, in plasma and urine. Five-tenths milliliter of urine or deproteinized plasma is evaporated and the residue analyzed isocratically by reversed-phase ion-pair chromatography, with measurement of the eluted nicotinic acid and nicotinuric acid at 254 nm. Nicotinic acid, nicotinuric a...

Acetylcholine (ACh) release onto nicotinic receptors directly activates subsets of inhibitory interneurons in hippocampal CA1. However, the specific interneurons activated and their effect on the hippocampal network is not completely understood. Therefore, we investigated subsets of hippocampal CA1 interneurons that respond to ACh release through the activation of nicotinic receptors and the po...

BACKGROUND Volatile anesthetics inhibit nicotinic acetylcholine receptors at subanesthetic concentrations. In both animal and human studies, similar concentrations of volatile anesthetics have been associated with increased sensitivity to pain. Nicotinic analgesia is thought to involve the enhanced release of norepinephrine. These studies are intended as a "proof of concept" that alteration of ...

Neuronal nicotinic acetylcholine (ACh) receptors are ligand-gated, cation-selective ion channels. Nicotinic receptors containing alpha4, alpha6, beta2, and beta3 subunits are expressed in midbrain dopaminergic neurons, and they are implicated in the response to smoked nicotine. Here, we have studied the cell biological and biophysical properties of receptors containing alpha6 and beta3 subunits...

The G-protein-coupled receptor GPR109A (HM74A/PUMA-G) has recently been shown to function as a receptor for nicotinic acid (niacin) and to mediate its antilipolytic effects. Nicotinic acid is able to strongly raise plasma levels of high-density lipoprotein cholesterol, a property that distinguishes nicotinic acid from other lipid-lowering drugs. To investigate the structural determinants of GPR...

Standard treatment of poisoning by organophosphorus anticholinesterases uses atropine to reduce the muscarinic effects of acetylcholine accumulation and oximes to reactivate acetylcholinesterase (the effectiveness of which depends on the specific anticholinesterase), but does not directly address the nicotinic effects of poisoning. Bispyridinium molecules which act as noncompetitive antagonists...

The catestatin fragment of chromogranin A is an endogenous inhibitor of nicotinic cholinergic transmission, functioning in negative feedback control of catecholamine secretion. We explored naturally occurring polymorphisms in the amino acid sequence of catestatin. Three human variants were identified: Gly364Ser, Pro370Leu, and Arg374Gln. Variants were tested for ability to inhibit four nicotini...

Ginsenosides is a low molecular weight substance found in ginseng as one of the active ingredients. Ginsenosides, like other herbal medicines, has a wide range of neuropharmacological actions including neuroprotective effects. The α9α10 nicotinic acetylcholine receptor is one of numerous nicotinic acetylcholine receptors that exists as a heteropentameric form in auditory hair cells of the cochl...