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Journal of the Royal Society, Interface Mar 2010Many cephalopods exhibit remarkable dermal iridescence, a component of their complex, dynamic camouflage and communication. In the species Euprymna scolopes, the...
Many cephalopods exhibit remarkable dermal iridescence, a component of their complex, dynamic camouflage and communication. In the species Euprymna scolopes, the light-organ iridescence is static and is due to reflectin protein-based platelets assembled into lamellar thin-film reflectors called iridosomes, contained within iridescent cells called iridocytes. Squid in the family Loliginidae appear to be unique in which the dermis possesses a dynamic iridescent component with reflective, coloured structures that are assembled and disassembled under the control of the muscarinic cholinergic system and the associated neurotransmitter acetylcholine (ACh). Here we present the sequences and characterization of three new members of the reflectin family associated with the dynamically changeable iridescence in Loligo and not found in static Euprymna iridophores. In addition, we show that application of genistein, a protein tyrosine kinase inhibitor, suppresses ACh- and calcium-induced iridescence in Loligo. We further demonstrate that two of these novel reflectins are extensively phosphorylated in concert with the activation of iridescence by exogenous ACh. This phosphorylation and the correlated iridescence can be blocked with genistein. Our results suggest that tyrosine phosphorylation of reflectin proteins is involved in the regulation of dynamic iridescence in Loligo.
Topics: Acetylcholine; Amino Acid Sequence; Animals; Color; Genistein; Loligo; Molecular Sequence Data; Phosphorylation; Proteins; Sequence Alignment; Signal Transduction; Skin
PubMed: 19776150
DOI: 10.1098/rsif.2009.0299 -
The Biochemical Journal Aug 1959
Topics: Acetylcholine; Brain; Brain Chemistry
PubMed: 13844484
DOI: 10.1042/bj0720694 -
Journal of the American College of... Mar 1992To examine the constrictor response of the infarct-related stenotic coronary artery in comparison with that of noninfarct-related stenotic arteries, acetylcholine in... (Comparative Study)
Comparative Study
Effect of acetylcholine on the highly stenotic coronary artery: difference between the constrictor response of the infarct-related coronary artery and that of the noninfarct-related artery.
To examine the constrictor response of the infarct-related stenotic coronary artery in comparison with that of noninfarct-related stenotic arteries, acetylcholine in maximal doses of 100 micrograms for the left and 50 micrograms for the right coronary artery was injected into the 16 infarct-related coronary arteries of 16 patients with previous myocardial infarction (group 1) and into 19 stenotic coronary arteries of 16 patients with stable angina without myocardial infarction (group 2). Acetylcholine's effects on lumen diameter and area were quantitatively analyzed at the stenotic segment and its proximal segment without significant stenosis. Acetylcholine decreased lumen diameter and area at the stenotic segments from 0.72 +/- 0.18 to 0.18 +/- 0.33 mm and from 0.45 +/- 0.22 to 0.10 +/- 0.22 mm2, respectively, in group 1 (both p less than 0.01) and from 0.75 +/- 0.22 to 0.49 +/- 0.30 mm and 0.48 +/- 0.29 to 0.26 +/- 0.23 mm2, respectively, in group 2 (both p less than 0.01). Acetylcholine decreased the diameter and area at the proximal segment from 2.71 +/- 0.75 to 2.38 +/- 0.6 mm and from 6.18 +/- 3.4 to 4.71 +/- 2.23 mm2, respectively, in group 1 (both p less than 0.01) and from 2.31 +/- 0.67 to 1.95 +/- 0.59 mm and from 4.5 +/- 2.97 to 3.22 +/- 1.96 mm2, respectively, in group 2 (both p less than 0.01). The changes in diameter and area at the stenotic segment in group 1 were significantly greater than those in group 2 (both p less than 0.01); there were no significant differences between groups in the changes at the proximal segment.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Acetylcholine; Angina Pectoris; Constriction, Pathologic; Coronary Angiography; Coronary Vessels; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Infarction; Vasoconstriction
PubMed: 1545069
DOI: 10.1016/0735-1097(92)90513-m -
Revista de NeurologiaThe main neurochemical alteration in diffuse Lewy body disease (DLBD) is the cholinergic deficit in the cerebral cortex, which involves mainly cholin-acetyl-transferase.... (Review)
Review
INTRODUCTION AND DEVELOPMENT
The main neurochemical alteration in diffuse Lewy body disease (DLBD) is the cholinergic deficit in the cerebral cortex, which involves mainly cholin-acetyl-transferase. There have been also described dopamine deficiency and alterations affecting other neurotransmitters and neuromodulators, such as serotonin, noradrenaline, neuropeptides, etc. Cerebral perfusion and glucose metabolism studies usually show diffuse hypoperfusion or hypometabolism, with higher alteration of associative cortex, including occipital involvement. Several studies have shown increased markers of oxidative stress in brain and other tissues, suggesting its possible role in the pathogenesis of DLBD.
CONCLUSIONS
Acetylcholinesterase inhibitors seem to improve cognitive and conductual symptoms, although their usefulness according evidence-based medicine criteria is weak. Some patients need atypical neuroleptics at low doses to get the symptomatic control of conductual alterations.
Topics: Acetylcholine; Brain Chemistry; Cerebrovascular Circulation; Choline O-Acetyltransferase; Cholinesterase Inhibitors; Humans; Lewy Body Disease; Oxidative Stress
PubMed: 16676279
DOI: No ID Found -
Applied and Environmental Microbiology Aug 1977The isolation, extraction, and spectrophotometric determination of acetylcholine from Lactobacillus plantarum ATCC 10241 is described. Acetylcholine was extracted with a...
The isolation, extraction, and spectrophotometric determination of acetylcholine from Lactobacillus plantarum ATCC 10241 is described. Acetylcholine was extracted with a mixture of sodium tetraphenylboron-butylethylketone-acetonitrile and was measured enzymatically at 340 nm.
Topics: Acetonitriles; Acetylcholine; Ketones; Lactobacillus; Spectrophotometry; Tetraphenylborate
PubMed: 907345
DOI: 10.1128/aem.34.2.237-239.1977 -
British Journal of Pharmacology Nov 19701. Cortical slices from rat brain were incubated in media containing the irreversible cholinesterase inhibitor soman and a high KCl concentration, and the release and...
1. Cortical slices from rat brain were incubated in media containing the irreversible cholinesterase inhibitor soman and a high KCl concentration, and the release and synthesis of acetylcholine (ACh) were determined.2. Atropine enhanced the release and synthesis of ACh.3. Tetrodotoxin, a substance which blocks nervous conduction, did not influence the release and synthesis of ACh, in the absence or in the presence of atropine. Therefore the nerve endings are probably the site at which atropine acts when stimulating the release and synthesis of ACh.4. Pretreatment of the slices with botulinum type A toxin partially blocked the release and synthesis of ACh and reduced the extra amounts of ACh released and synthesized under the influence of atropine.5. Lowering the calcium or raising the magnesium concentration in the incubation medium reduced the release and synthesis of ACh and their enhancement by atropine.6. Physostigmine decreased the total extractable ACh content of the slices during incubation in a 25 mM KCl containing medium. This decrease was nearly prevented when the release and synthesis of ACh were inhibited by omission of the calcium ions from the medium, but was enhanced by atropine.7. The observations made with pretreatment by botulinum type A toxin, with changes in the calcium and magnesium concentration as well as with physostigmine, all support the theory that it is primarily the release of ACh which is enhanced by atropine and that its stimulating action on the synthesis results from the increased release.
Topics: Acetylcholine; Animals; Atropine; Botulinum Toxins; Calcium; Cerebral Cortex; Chlorides; Cholinesterase Inhibitors
PubMed: 5497792
DOI: 10.1111/j.1476-5381.1970.tb10622.x -
Transactions of the American... 1971
Clinical Trial Comparative Study Randomized Controlled Trial
Topics: Acetylcholine; Carbachol; Cataract Extraction; Clinical Trials as Topic; Humans; Miotics; Ophthalmic Solutions; Time Factors; Tissue Adhesions
PubMed: 4949377
DOI: No ID Found -
The European Respiratory Journal Oct 1997
Topics: Acetylcholine; Administration, Inhalation; Animals; Binding, Competitive; Body Fluids; Bronchoconstriction; Diffusion; Models, Theoretical; Mucous Membrane; Permeability; Pulmonary Alveoli; Rats; Respiratory Physiological Phenomena; Species Specificity; Surface Properties; Surface-Active Agents
PubMed: 9387939
DOI: 10.1183/09031936.97.10102194 -
Contrast Media & Molecular Imaging 2011Choline as a reporter molecule has been investigated by in vivo magnetic resonance for almost three decades. Accumulation of choline metabolites (mainly the...
Choline as a reporter molecule has been investigated by in vivo magnetic resonance for almost three decades. Accumulation of choline metabolites (mainly the phosphorylated forms) had been observed in malignancy in preclinical models, ex-vivo, in vivo and in patients. The combined choline metabolite signal appears in (1) H-MRS of the brain and its relative intensity had been used as a diagnostic factor in various conditions. The advent of spin hyperpolarization methods for in vivo use has raised interest in the ability to follow the physiological metabolism of choline into acetylcholine in the brain. Here we present a stable-isotope labeled choline analog, [1,1,2,2-D(4) ,2-(13) C]choline chloride, that is suitable for this purpose. In this analog, the (13) C position showed 24% polarization in the liquid state, following DNP hyperpolarization. This nucleus also showed a long T(1) (35 s) at 11.8 T and 25 °C, which is a prerequisite for hyperpolarized studies. The chemical shift of this (13) C position differentiates choline and acetylcholine from each other and from the other water-soluble choline metabolites, namely phosphocholine and betaine. Enzymatic studies using an acetyltransferase enzyme showed the synthesis of the deuterated-acetylcholine form at thermal equilibrium conditions and in a hyperpolarized state. Analysis using a comprehensive model showed that the T(1) of the formed hyperpolarized [1,1,2,2-D(4) ,2-(13) C]acetylcholine was 34 s at 14.1 T and 37 °C. We conclude that [1,1,2,2-D(4) ,2-(13) C]choline chloride is a promising new molecular probe for hyperpolarized metabolic studies and discuss the factors related to its possible use in vivo.
Topics: Acetylcholine; Animals; Betaine; Brain Chemistry; Choline; Humans; Magnetic Resonance Spectroscopy; Metabolomics; Molecular Probes; Phosphorylcholine
PubMed: 21698772
DOI: 10.1002/cmmi.418 -
Japanese Journal of Pharmacology Aug 1975Effects of acetylcholine (ACh) and norepinephrine on atrial contractility and pacemaker activity were investigated in isolated and blood-perfused canine atrium... (Comparative Study)
Comparative Study
Effects of acetylcholine (ACh) and norepinephrine on atrial contractility and pacemaker activity were investigated in isolated and blood-perfused canine atrium preparations whith a support dog which were suspended in the blood-filled bath kept at 37 degrees C. The drug was given in two forms of administration, i.e., intraarterial injection into the cannulated sinus node artery or direct administration into the bath. ACh administered into the bath produced a significant decrease in the developed tension from a concentration of 10(-5) g/ml and norepinephrine produced a significant increase in the developed tension from 3 X 10(-6) g/ml. An injection via the sinus node artery resulted in 300 and 100 times greater response to ACh and norepinephrine, respectively, in the tension development. In atrial pacemaker activity, ACh given into the bath did not produce a dose-related decrease while norepinephrine produced a dose-related increase frequently accompanied by an irregularity of rhythmicity.
Topics: Acetylcholine; Administration, Topical; Animals; Dogs; Dose-Response Relationship, Drug; Female; Heart Atria; Injections, Intra-Arterial; Male; Myocardial Contraction; Norepinephrine; Perfusion
PubMed: 1206813
DOI: 10.1254/jjp.25.433