Histamine In Pig Platelet Dense Granules

1981 ◽  
Author(s):  
M H Fukami ◽  
K Ugurbil ◽  
H Holmsen ◽  
G L Pakstis ◽  
C A Dangelmaier
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Paper Chromatography ◽  
Chemical Shifts ◽  
Ph Dependence ◽  
Dense Granule ◽  
Major Constituent ◽  
Pharmacological Effects ◽  
Dense Granules

In the course of high resolution nuclear magnetic resonance (n.m.r.) studies of dense granule storage complexes, an amine with two aromatic protons was observed in a proton n.m.r. spectrum of dense granules isolated from pig platelets. This amine was identified as histamine by the exact coincidence of the n.m.r. peaks of added histamine with the unknown peaks in the extract. The pH dependence of chemical shifts, paper chromatography and flurometric analysis after coupling with o-phthalaldehyde confirmed the identification. The concentration of histamine in isolated dense granules was about 700 nmol/mg of protein (n=3) or 1.6 times that of serotonin. In intact platelets, the histamine content was 11 nmol/mg compared to 7 nmol/mg of serotonin. The addition of 1 unit/ml of thrombin to suspensions of washed pig platelets resulted in the secretion of more than 90% of the histamine under conditions in which only 3.8% of thelactate dehydrogenase appeared extracellularly. These findings indicate that histamine is a major constituent of dense granules in pig platelets which can be released during hemostasis and thrombosis and may exert its pharmacological effects under these conditions.

THE ANALYSIS OF NUCLEAR MAGNETIC RESONANCE SPECTRA: III. PYRIDINE AND DEUTERATED PYRIDINES

1957 ◽  
Vol 35 (12) ◽  
pp. 1487-1495 ◽  
Author(s):  
W. G. Schneider ◽  
H. J. Bernstein ◽  
J. A. Pople
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Calculated Spectrum ◽  
Proton Resonance ◽  
Nuclear Magnetic Resonance Spectra ◽  
Spin Coupling Constants

The proton resonance spectra of pyridine, 2,6-pyridine-d2, 3-pyridine-d1, and 4-pyridine-d1 have been obtained for the pure liquids under conditions of high resolution. The spectra have been analyzed as proton groupings of AB2X2, AB2, perturbed ABX, and B2X2 respectively. The spin-coupling constants obtained from analysis of the simpler spectra of the deuterated molecules were used to suggest trial solutions for the analysis of the complicated AB2X2 spectrum of pyridine. A final set of chemical shifts and spin-coupling constants derived for pyridine give satisfactory agreement between the observed and calculated spectrum.

High-Resolution J-Scaling Nuclear Magnetic Resonance Spectra in Inhomogeneous Fields via Intermolecular Multiple-Quantum Coherences

2009 ◽  
Vol 63 (5) ◽  
pp. 585-590 ◽  
Author(s):  
Yanqin Lin ◽  
Zhong Chen ◽  
Shuhui Cai ◽  
Jianhui Zhong
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Chemical Shifts ◽  
Spin Systems ◽  
Coupling Constants ◽  
Multiple Quantum ◽  
J Coupling ◽  
Inhomogeneous Fields ◽  
J Coupling Constants

High-resolution nuclear magnetic resonance (NMR) spectroscopy with information on chemical shifts and J-coupling constants is a sensitive tool for studying physical, chemical, and biological properties of materials at the molecular level. In this paper, a pulse sequence is developed for acquiring high-resolution NMR spectra of liquid samples with J-scaling in inhomogeneous fields via two-dimensional intermolecular multiple-quantum coherence acquisitions. In the resulting one-dimensional projection spectra, apparent J-coupling constants were obtained with a scaling factor theoretically varying from zero (completely decoupled) to infinity relative to the original J-coupling constants while retaining information on chemical shifts, relative peak areas, and multiplet patterns. This allows either an accurate measurement of small J-coupling constants of weakly coupled spin systems or less crowded spectra for spin systems with J-splitting. Experimental observations and simulation results agree with theoretical analysis.

Metal – Aminopolycarboxylic Acid Complexes. III. Studies of Lead(II) – Tetraethylenepentaamineheptaacetic Acid in Aqueous Solution by Proton Nuclear Magnetic Resonance Spectroscopy

1971 ◽  
Vol 49 (12) ◽  
pp. 2096-2102 ◽  
Author(s):  
Peter Letkeman ◽  
Donald T. Sawyer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Electrostatic Interactions ◽  
Chemical Shifts ◽  
Ph Dependence ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Carboxylate Groups ◽  
Nitrogen Bonds ◽  
Nuclear Magnetic

Proton nuclear magnetic resonance (n.m.r.) spectroscopy and the pH dependence of the chemical shifts of the nonlabile protons have been used to determine the preferred protonation sites in tetraethylenepentaamineheptaacetic acid (TPHA). The nitrogen atoms are protonated more readily than the carboxylate groups with the sequence of protonation dependent on electrostatic interactions. The 1:1 Pb(II)–TPHA complex which is not protonated for solution conditions from pH 10 to 14, has five metal–nitrogen bonds. The coordinate bonds are labile so that rapid interconversion between nonequivalent configurations produces an average configuration in which the protons of the acetate groups exhibit single n.m.r. peaks. Protonation of the complex probably occurs in three stages. From pH 10 to pH 8 the preferred protonation sites are the terminal nitrogen atoms with the attendant elimination of the metal–nitrogen bonds. Increasing the acidity to pH 4 causes all but the central nitrogen site to be protonated. Below pH 4 the central nitrogen atom becomes protonated and causes further unwrapping of the complex.

The High Resolution NMR Spectra of Pesticides. II. The DDT-Type Compounds

1969 ◽  
Vol 52 (5) ◽  
pp. 1074-1092 ◽  
Author(s):  
L H Keith ◽  
A L Alford ◽  
A W Garrison
Keyword(s):  
Nuclear Magnetic Resonance ◽  
High Resolution ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Aromatic Rings ◽  
Nuclear Magnetic Resonance Spectra ◽  
High Resolution Nmr ◽  
Related Compounds ◽  
Deshielding Effect

Abstract The high resolution nuclear magnetic resonance spectra of the DDT class of pesticides and related compounds are discussed, including a study of the resonances of the aromatic protons as they are affected by various substiluents. The CCl3 moiety on the α-carbon strongly deshields the ortho protons on the aromatic rings, and this deshielding effect is greatly enhanced by substitution of a chlorine ortho rather than para on the aromatic ring. These deshielding effects are explained by a consideration of the electronegativity of the substituents and the stereochemistry of the molecule. The chemical shifts and coupling constants are tabulated.

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