Proton nuclear magnetic resonance studies of mast cell histamine
The state of histamine in mast cells was studied by /sup 1/H NMR spectroscopy. Spectra were measured for histamine in situ in intact mast cells, for histamine in suspensions of mast cell granule matrices that had been stripped of their membranes, and for histamine in solutions of heparin. The /sup 1/H NMR spectrum of intact mast cells is relatively simple, consisting predominantly of resonances for intracellular histamine superimposed on a weaker background of resonances from heparin and proteins of the cells. All of the intracellular histamine contributes of the NMR signals, indicating it must be relatively mobile and not rigidly associated with the negatively charged granule matrix. Spectra for intracellular histamine and for histamine in granule matrices are similar, indicating the latter to be a reasonable model for the in situ situation. The dynamics of binding of histamine by granule matrices and by heparin are considerably different; exchange of histamine between the bulk water and the granule matrices is slow on the /sup 1/H NMR time scale, whereas exchange between the free and bound forms in heparin solution is fast. The chemical shifts of resonances for histamine in mast cells are pH dependent, decreasing as the intragranule pH increases without splitting or broadening. The results are interpreted to indicate that histamine in mast cells is relatively labile, with rapid exchange between histamine and pools of free histamine in water compartments confined in the granule matrix.
- Research Organization:
- Univ. of Alberta, Edmonton
- OSTI ID:
- 5560245
- Journal Information:
- Biochemistry; (United States), Vol. 26:22
- Country of Publication:
- United States
- Language:
- English
Similar Records
Studies on the pH gradient and histamine uptake of isolated mast cell granules
Biochemical and microscopic evidence for the internalization and degradation of heparin-containing mast cell granules by bovine endothelial cells
Related Subjects
HISTAMINE
NUCLEAR MAGNETIC RESONANCE
CHEMICAL SHIFT
HEAVY WATER
MAST CELLS
NMR SPECTRA
PH VALUE
PROTONS
AMINES
ANIMAL CELLS
AZOLES
BARYONS
CONNECTIVE TISSUE CELLS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
IMIDAZOLES
MAGNETIC RESONANCE
NUCLEONS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
RESONANCE
SOMATIC CELLS
SPECTRA
WATER
550601* - Medicine- Unsealed Radionuclides in Diagnostics