Home About us Contact
|
Home About us Contact | ||
|
|
||
AMPS Content (amp + content)
Selected AbstractsEvidence for cocaine and methylecgonidine stimulation of M2 muscarinic receptors in cultured human embryonic lung cellsBRITISH JOURNAL OF PHARMACOLOGY, Issue 2 2001Yinke Yang Muscarinic cholinoceptor stimulation leads to an increase in guanylyl cyclase activity and to a decrease in adenylyl cyclase activity. This study examined the effects of cocaine and methylecgonidine (MEG) on muscarinic receptors by measurement of cyclic GMP and cyclic AMP content in cultured human embryonic lung (HEL299) cells which specifically express M2 muscarinic receptors. A concentration-dependent increase in cyclic GMP production was observed in HEL299 cells incubated with carbachol, cocaine, or MEG for 24 h. The increase in cyclic GMP content was 3.6 fold for 1 ,M carbachol (P<0.01), 3.1 fold for 1 ,M cocaine (P<0.01), and 7.8 fold for 1 ,M MEG (P<0.001), respectively. This increase in cyclic GMP content was significantly attenuated or abolished by the muscarinic receptor antagonist atropine or the M2 blocker methoctramine. In contrast, cocaine, MEG, and carbachol produced a significant inhibition of cyclic AMP production in HEL299 cells. Compared to the control, HEL299 cells treated with 1 ,M cocaine decreased cyclic AMP production by 30%. MEG and carbachol at 1 ,M decreased cyclic AMP production by 37 and 38%, respectively. Atropine or methoctramine at 1 or 10 ,M significantly attenuated or abolished the cocaine-induced decrease in cyclic AMP production. However, the antagonists alone had neither an effect on cyclic GMP nor cyclic AMP production. Pretreatment of HEL299 cells with pertussis toxin prevented the cocaine-induced reduction of cyclic AMP production. Western blot analysis showed that HEL299 cells specifically express M2 muscarinic receptors without detectable M1 and M3. Incubation of HEL299 cells with cocaine, carbachol, and atropine did not alter the expression of M2 protein levels. However, the inducible isoform of nitric oxide synthase (iNOS) was induced in the presence of cocaine or carbachol and this induction was significantly attenuated after addition of atropine or methoctramine. The present data show that cocaine and MEG significantly affect cyclic GMP and cyclic AMP production in cultured HEL299 cells. Our results also show that these effects result from the drug-induced stimulation of M2 muscarinic receptors accompanied with no alterations of receptor expression. However, the induction of iNOS by cocaine may result in the increase in cyclic GMP production. British Journal of Pharmacology (2001) 132, 451,460; doi:10.1038/sj.bjp.0703819 [source] Preparation and evaluation of the highly cross-linked poly(1-hexadecane-co-trimethylolpropane trimethacrylate) monolithic column for capillary electrochromatographyELECTROPHORESIS, Issue 20 2009Minghua Lu Abstract In this paper, a novel highly cross-linked porous monolithic stationary phase having a long alkyl chain ligand (C16) was introduced and evaluated in CEC. The monolithic stationary phase was prepared by in situ copolymerization of 1-hexadecene, trimethylolpropane trimethacrylate, and 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) in the presence of ternary porogenic solvent (cyclohexanol/1,4-butanediol/water). In preparing monoliths, the ternary cross-linker trimethylolpropane trimethacrylate was usually applied to preparing molecularly imprinted polymers or molecularly imprinted solid-phase extraction, instead of binary cross-linker ethylene dimethacrylate. 1-Hexadecene was introduced to provide the non-polar sites (C16) for chromatographic retention, while AMPS was used to generate the EOF for transporting the mobile phase through the monolithic capillary. Monolithic columns were prepared by optimizing proportion of porogenic solvent and AMPS content in the polymerization solution as well as the cross-linkers. The monolithic stationary phases could generate a strong and stable EOF in various pH values and exhibit an RP-chromatographic behavior for neutral compounds. For charged compounds, the separation was mainly based on the association of hydrophobic, electrostatic and electrophoretic interaction. [source] Physically and Chemically Cross-Linked Poly{[(maleic anhydride)- alt -styrene]- co -(2-acrylamido-2-methyl-1-propanesulfonic acid)}/Poly(ethylene glycol) Proton-Exchange MembranesMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 2 2007lser G. Devrim Abstract Novel proton exchange membranes were solvent-cast from DMF solutions of the terpolymers poly[(MA- alt -S)- co -AMPS], containing hydrophobic phenyl and reactive hydrophilic carboxylic and organo-sulfonic acid fragments with different compositions, and PEGs with different molecular weights and amounts. These membranes were formed as a result of physical (via H-bonding) and chemical (via PEG) cross-linking. The structures of membranes were confirmed by FT-IR and 1H- and 13C NMR spectroscopy. Mechanical and thermal properties, swellability, and proton conductivity of these membranes were significantly affected both by the chemical composition of the terpolymers (mainly the AMPS content) and also the cross-linker (PEG) molecular weight and content in the final form of the membranes. It was concluded that the membranes prepared by using the terpolymer with an AMPS content of 36.84 mol-% and PEG with a molecular weight of 1,450 and with an initial PEG content of 30 wt.-% are the most suitable ones for fuel cell applications. [source] A new composite sorbent for water and dye uptake: Highly swollen acrylamide/2-acrylamido-2-methyl-1-propanesulfonic acid/clay hydrogels crosslinked by 1,4-butanediol dimethacrylatePOLYMER COMPOSITES, Issue 1 2009Semiha Kundakci A novel type of highly swollen hydrogels based on acrylamide (AAm) with 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and clay such as bentonite (Bent) crosslinked by 1,4-butanediol dimethacrylate (BDMA) was prepared by free radical solution polymerization in aqueous media. Water uptake and dye sorption properties of polyelectrolyte AAm/AMPS hydrogels and AAm/AMPS/Bent composite hydrogels were investigated as a function of composition to find materials with swelling and sorption properties. FTIR analyses were made. Swelling experiments were performed in water and dye solution at 25°C, gravimetrically. Highly swollen AAm/AMPS and AAm/AMPS/Bent hydrogels were used in experiments on sorption of water-soluble monovalent cationic dye such as Lauths violet "LV, (Thionin)." Swelling of AAm/AMPS hydrogels was increased up to 1,920,9,222% in water and 867,4,644% in LV solutions, while AAm hydrogels swelled 905% in water and swelling of AAm/AMPS/Bent hydrogels was increased up to 2,756,10,422% in water and 1,200,3,332% in LV solutions, while AAm/Bent hydrogels swelled 849% in water. Some swelling kinetic and diffusional parameters were found. Water and LV diffusion into hydrogels was found to be non-Fickian in character. For sorption of cationic dye, LV into AAm/AMPS and AAm/AMPS/Bent hydrogel was studied by batch sorption technique at 25°C. The amount of the dye sorbed per unit mass removal effiency and partition coefficient of the hydrogels was investigated. The influence of AMPS content in the hydrogels to sorption was examined. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers [source] | ||||||||||