Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.8 (cholinesterase)
 12,691 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study was designed to characterise the muscarinic receptor subtype responsible for acetylcholine-mediated in vitro pulmonary artery relaxation in rats and the importance of the presence of neostigmine (an anti-cholinesterase) during receptor characterisation. Cumulative administration of acetylcholine elicited concentration-dependent relaxation of phenylephrine (1 microM) precontracted preparations. Inclusion of neostigmine (10 microM) caused a parallel leftward shift with an increase of the pD(2) value (7.09 vs. 6.43) of the concentration-response curve of acetylcholine. The magnitude of maximum relaxation, however, was not affected. Using a range of conventional muscarinic receptor antagonists (atropine, pirenzepine, methoctramine, p-FHHSiD and tropicamide) and the highly selective Green Mamba muscarinic toxins (MT-3 and MT-7), it was found that muscarinic M(3) receptors are probably responsible for endothelium-dependent relaxation of the pulmonary artery upon acetylcholine challenge. Preincubation with N(G)-nitro-L-arginine methyl ester (L-NAME, 20 microM, a nitric oxide synthase inhibitor), but not N(G)-nitro-D-arginine methyl ester (D-NAME, 20 microM), abolished acetylcholine-elicited relaxation. Moreover, 6-anilino-5,8-quinolinedione (LY 83583, 1 microM) and methylene blue (1 microM) (both are guanylate cyclase inhibitors) markedly attenuated acetylcholine-elicited relaxation. However, the presence of indomethacin (3 microM, a cyclo-oxygenase inhibitor), (-)-perillic acid (30 microM, a p21(ras) blocker), 2-[2'-amino-3'-methoxy-phenyl]-oxana-phthalen-4-one (PD 98059) (10 microM, a p42/p44 mitogen-activated protein kinase inhibitor), 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB 203580) (1 microM, a p38 mitogen-activated protein kinase blocker), wortmannin (500 nM, a phosphatidylinositol-3 kinase inhibitor) and genistein (10 microM, a tyrosine kinase blocker) failed to alter acetylcholine-provoked pulmonary arterial relaxation. These results suggest that acetylcholine caused pulmonary arterial relaxation through the activation of muscarinic M(3) receptors in the endothelium. Moreover, the p21(ras)/mitogen-activated protein kinase pathway seems to play no role in mediating acetylcholine-elicited relaxation.
 ...
PMID:Role of mitogen-activated protein kinase pathway in acetylcholine-mediated in vitro relaxation of rat pulmonary artery. 1175 66

In the course of examining the actions of major human bile acids on cholinergic receptors, we discovered that conjugates of lithocholic acid are partial muscarinic agonists. In the present communication, we report that conjugates of deoxycholic acid (DC) act as cholinergic muscarinic receptor antagonists. Chinese hamster ovary (CHO) cells expressing rat M3-muscarinic receptors were used to test bile acids for inhibition of radioligand [N- (3)H-methylscopolamine ((3)H-NMS)] binding; alteration of inositol phosphate (IP) formation; mitogen-activated protein (MAP) kinase phosphorylation and cell toxicity. We observed approximately 18.8, 30.3 and 37.1% inhibition of (3)H-NMS binding with DC and its glycine (DCG) and taurine (DCT) conjugates, respectively (all 100 micromol/l, p < 0.01). DCT and DCG inhibited acetylcholine-induced increases in IP formation and MAP kinase phosphorylation (p44 and p42 ERK). DCG and DCT did not alter trypan blue exclusion or lactate dehydrogenase release from CHO-M3 cells. We observed the following rank order of potency (IC(50) micromol/l) for inhibition of (3)H-NMS by muscarinic antagonists and bile acids: NMS (0.0004) > 4-DAMP (0.009) > atropine (0.012) > DCT (170) > DCG (250). None of the bile acids tested were hydrolyzed by recombinant cholinesterase. At concentrations achieved in human bile, DC derivatives are natural muscarinic antagonists.
 ...
PMID:Deoxycholic acid conjugates are muscarinic cholinergic receptor antagonists. 1211 52

Two novel neuroprotective cholinesterase (ChE) inhibitors, TV3326, (N-propargyl-(3R) aminoindan-5-yl)-ethyl methyl carbamate, and TV3279, (N-propargyl-(3S) aminoindan-5-yl)-ethyl methyl carbamate, were derived from rasagiline for the treatment of Alzheimer's disease (AD). TV3326 also inhibits monoamine oxidase (MAO)-A and -B, whereas its S-isomer, TV3279, lacks MAO inhibitory activity. The action of these drugs in the regulation of amyloid precursor protein (APP) processing, using rat PC12 and human SH-SY5Y neuroblastoma cells, was examined. Both isomers stimulated the release of the non-amyloidogenic a-secretase form of soluble APP (sAPPalpha) from these cell lines. The increases in sAPPalpha, induced by TV3326 and TV3279, were dose-dependent (0.1-100 mM) and blocked by the hydroxamic acid-based metalloprotease inhibitor, Ro31-9790, suggesting mediation via a-secretase activity. Using several signal transduction inhibitors, we identified the involvement of protein kinase C (PKC), mitogen-activated protein (MAP) kinase, and tyrosine kinase-dependent pathways in the enhancement of sAPPalpha release by TV3326 and TV3279. In addition, both drugs directly induced the phosphorylation of p44 and p42 MAP kinase, which was abolished by the specific inhibitors of MAP kinase activation, PD98059 and U0126. These data suggest a novel pharmacological mechanism whereby these ChE inhibitors regulate the secretory processes of APP via activation of the MAP kinase pathway.
 ...
PMID:Involvement of MAP kinase in the regulation of amyloid precursor protein processing by novel cholinesterase inhibitors derived from rasagiline. 1220 96

Two novel neuroprotective cholinesterase (ChE) inhibitors, TV3326 and TV3279 [(N-propargyl-(3R) and (3S) aminoindan-5-yl)-ethyl methyl carbamate], respectively were derived from rasagiline, for the treatment of Alzheimer's disease (AD). TV3326 also inhibits monoamine oxidase (MAO)-A and B, while its S-isomer, TV3279, lacks MAO-inhibitory activity. The actions of these drugs in the regulation of the amyloid precursor protein (APP) processing using rat PC12 and human SH-SY5Y neuroblastoma cells were examined. Both isomers stimulated the release of the non-amyloidogenic alpha-secretase form of soluble APP (sAPPalpha) from these cell lines. The increases in sAPPalpha, induced by TV3326 and TV3279, were dose-dependent (0.1-100 micro M) and blocked by the hydroxamic acid-based metalloprotease inhibitor, Ro31-9790, suggesting mediation via alpha-secretase activity. Using several signal transduction inhibitors, the involvement of protein kinase C (PKC), mitogen-activated protein (MAP) kinase, and tyrosine kinase-dependent pathways in the enhancement of sAPPalpha release by TV3326 and TV3279 was identified. In addition, both drugs directly induced the phosphorylation of p44 and p42 MAP kinase, which was abolished by the specific inhibitors of MAP kinase activation, PD98059 and U0126. These data suggest a novel pharmacological mechanism, whereby these ChE inhibitors regulate the secretary processes of APP via activation of the MAP kinase pathway.
 ...
PMID:Amyloid processing and signal transduction properties of antiparkinson-antialzheimer neuroprotective drugs rasagiline and TV3326. 1285 32

The anti-Parkinsonian, irreversible, selective monoamine oxidase (MAO)-B inhibitors, selegiline (deprenyl, (R)-N-methyl-N-(1-phenylpropan-2-yl) prop-2-yn-1-amine) and rasagiline (Azilect, N-propargyl-1(R)-aminoindan), have been proven to possess neuroprotective/neurorestorative activities in cell cultures and animal models of neurodegenerative diseases. Structure-activity studies provide evidence that neuroprotection is associated with some intrinsic pharmacological action of the propargylamine moiety in these drugs. This indication and recent therapeutic approaches, entailing new drug candidates possessing diverse pharmacological properties and acting on multiple targets, have stimulated the development of two multifunctional chimeric propargylamine-derivatives: 1) ladostigil (TV3326, [(N-propargyl-(3R) 1-(R)-aminoindan-5yl)-ethyl methyl carbamate)], which combines the pharmacophore of rasagiline, with the carbamate moiety of the cholinesterase inhibitor rivastigmine, as a potential treatment for Alzheimer's disease and Lewy body disease; and 2) M30 5-[(N-methyl-N-propargylaminomethyl)-8-hydroxyquinoline], where the propargylamine moiety of rasagiline was embedded onto the backbone of the neuroprotective and brain permeable iron chelator 8-hydroxyquinoline-derivative, VK28 as a potential treatment for various neurodegenerative disorders. Both multifunctional propargylamine-derivatives were found to possess neuroprotective and anti-apoptotic properties. An additional and new neuroprotective effect, shared by the propargylamine-derivative compounds, is related to their ability to regulate the processing of amyloid-beta protein precursor (AbetaPP) by the non-amyloidogenic alpha-secretase pathway. This effect was shown to involve activation of p42/44 mitogen-activated protein kinase (MAPK) and protein kinase C (PKC) signaling pathway. This review will summarize and discuss current research, focused on the effect of propargylamine-related derivatives on the proteolytic processing of AbetaPP and signal transduction mechanisms.
 ...
PMID:Propargylamine containing compounds as modulators of proteolytic cleavage of amyloid-beta protein precursor: involvement of MAPK and PKC activation. 2055 37