Modifications induced by plasma of gestational hypertensive women on the Na+/K+-ATPase obtained from human placenta

N. Cester, R. A. Rabini, A. L. Tranquilli, G. Lucarelli, E. Salvolini, R. Staffolani, E. Amler, G. Zolese, L. Mazzanti

Research output: Contribution to journalArticle

Abstract

In order to investigate the molecular mechanisms of the inhibition of Na+/K+-ATPase in Gestational Hypertension (GH), we incubated Na+K+-ATPase purified from human placenta of 6 healthy normotensive women with plasma from 6 GH women and 6 healthy controls. We determined the enzyme activity by the method of Esman, and the anthroyl-ouabain-binding capacity, dissociation constant (K(d)) and average lifetime values (τ) by the static and dynamic fluorescence of anthroyl-ouabain. The lipid annulus of the enzyme was studied by static and dynamic fluorescence of 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). The addition of total and protein-free GH plasma to normal Na+/K+-ATPase significantly inhibited the enzymatic activity even at the lowest concentration studied (1:100), as well as the ouabain-binding capacity, K(d) and τ. GH plasma significantly decreased the fluorescence polarization and lifetime values of TMA-DPH. These observations indicate that the inhibition caused by GH plasma on Na+/K+-ATPase might be due to a reduction of the number of active molecules or a modification of the ouabain-binding site suggesting the existence of digitalis-like factor. A link between the modification of the lipid moiety of the enzyme and the Na+/K+-ATPase inhibition might be hypothesized.

Original languageEnglish
Pages (from-to)125-129
Number of pages5
JournalMolecular and Cellular Biochemistry
Volume170
Issue number1-2
DOIs
Publication statusPublished - 1997

Keywords

  • Activity
  • Fluorescence
  • Gestational hypertension
  • Ouabain
  • Plasma

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology

Fingerprint Dive into the research topics of 'Modifications induced by plasma of gestational hypertensive women on the Na<sup>+</sup>/K<sup>+</sup>-ATPase obtained from human placenta'. Together they form a unique fingerprint.

  • Cite this

    Cester, N., Rabini, R. A., Tranquilli, A. L., Lucarelli, G., Salvolini, E., Staffolani, R., Amler, E., Zolese, G., & Mazzanti, L. (1997). Modifications induced by plasma of gestational hypertensive women on the Na+/K+-ATPase obtained from human placenta. Molecular and Cellular Biochemistry, 170(1-2), 125-129. https://doi.org/10.1023/A:1006849318305