Basic Research in Cardiology

, Volume 75, Issue 3, pp 433–437 | Cite as

Stimulation of human cardiac adenylate cyclase by vanadate

  • W. Krawietz
  • K. Werdan
  • E. Erdmann
Original Contributions

Summary

Experiments have been carried out to characterize the influence of the positive inotropic trace element vanadium (used as Na3VO4) on β-adrenergic receptor coupled adenylate cyclase activity from human myocardium. Na3VO4 (10−4 M) stimulates basal activity as well as isoprenaline (10 μM)- and Mg2+ (20 mM)-activated enzyme activity 1.5–2.4-fold. In contrast, adenylate cyclase activity in the presence of maximally activating concentrations of Gpp(NH)p (10 μM) cannot be further increased by Na3VO4. The results confirm the assumption (5) that vanadate stimulates adenylate cyclase by interacting with the nucleotide-binding site of this enzyme.

Keywords

Public Health Enzyme Activity Adenylate Cyclase Basal Activity Isoprenalin 

Stimulation der Adenylatzyklase in menschlichem Herzmuskelgewebe durch Vanadat

Zusammenfassung

Es wurde der Einfluß des positiv inotropen Spurenelementes Vanadium (verwendet als Na3VO4) auf die β-Rezeptor-gekoppelte Adenylatzyklaseaktivität aus menschlichem Herzmuskelgewebe untersucht. Na3VO4 (10−4 M) stimuliert 1,5–2,4fach sowohl die Basalaktivität als auch die durch Isoprenalin (10 μM) und durch Mg2+ (20 mM) aktivierte Enzymaktivität. Im Gegensatz dazu kann die durch Gpp(NH)p (10 μm) maximal aktivierte Adenylatzyklaseaktivität durch Vanadat nicht weiter gesteigert werden. Die experimentellen Befunde bestärken die Annahme (5), daß Vanadat die Adenylatzyklase über eine Wechselwirkung mit der Nukleotidbindungsstelle des Enzyms stimuliert.

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Copyright information

© Dr. Dietrich Steinkopff Verlag 1980

Authors and Affiliations

  • W. Krawietz
    • 1
  • K. Werdan
    • 1
  • E. Erdmann
    • 1
  1. 1.Klinikum GroßhadernMedizinische Klinik I der Universität MünchenMünchenGermany

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