Effect of superoxide radical on Ca sup 2+ pumps of coronary artery

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · American Journal of Physiology; (USA)

OSTI ID:6834378

Grover, A K; Samson, S E ^[1]

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1. McMaster Univ., Hamilton, Ontario (Canada)

The effect of superoxide radical on the azide-insensitive ATP-dependent of Ca{sup 2+}-transport by a plasma membrane (PM)-enriched fraction (F2) and an endoplasmic reticulum (ER)-enriched fraction (F3) isolated from pig coronary artery was examined using xanthine oxidase plus xanthine to generate superoxide ions. A preincubation with xanthine oxidase plus xanthine at 37{degree}C preferentially inactivated the oxalate-stimulated Ca{sup 2+} uptake by the F3 fraction rather than the phosphate-stimulated uptake by the F2 fraction, indicating that the Ca{sup 2+} pump in the ER was more susceptible to this free radical. The inactivation of the Ca{sup 2+} uptake depended on the concentrations of xanthine oxidase and xanthine in the preincubation mixture as well as on the preincubation time. Furthermore, the inclusion of superoxide dismutase in the preincubation mixture prevented the inactivation. Thus the inactivation was caused by superoxide radical. Preincubation with xanthine oxidase plus xanthine, however, altered the half-life of efflux of Ca{sup 2+} from these vesicles only marginally. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the F3 fraction showed formation of a Ca{sup 2+}-dependent acid stable phosphoenzyme at 0{degree}C predominantly at a protein band corresponding to 100 kDa. The authors conclude that superoxide radical inactivates the ER Ca{sup 2+} transport by lowering the level of the phosphoenzyme.

• OSTI ID: 6834378
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:3; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
AROMATICS
ARTERIES
AZAARENES
AZIDES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BLOOD VESSELS
BODY
CALCIUM 45
CALCIUM ISOTOPES
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CELL MEMBRANES
CORONARIES
DAYS LIVING RADIOISOTOPES
DOSE-RESPONSE RELATIONSHIPS
ENDOPLASMIC RETICULUM
ENZYMES
EVEN-ODD NUCLEI
HETEROCYCLIC COMPOUNDS
INACTIVATION
INTERMEDIATE MASS NUCLEI
ISOTOPES
MEMBRANE TRANSPORT
MEMBRANES
NITROGEN COMPOUNDS
NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANOIDS
ORGANS
OXIDOREDUCTASES
PURINES
RADICALS
RADIOISOTOPES
REACTION INTERMEDIATES
SUPEROXIDE DISMUTASE
SUPEROXIDE RADICALS
UPTAKE
XANTHINES