Ouabain-Like Na+,K+-ATPase Inhibitory Activity of a Plasma Extract in Normal Pregnancy and Pregnancy Induced Hypertension.
-
- Miyagi Hiroko
- Department of Obstetrics & Gynecology, School of Medicine, Faculty of Medicine, University of the Ryukyus
-
- Higuchi Makie
- Department of Pharmacology, Faculty of Medicine, University of the Ryukyus
-
- Nakayama Michio
- Department of Obstetrics & Gynecology, School of Medicine, Faculty of Medicine, University of the Ryukyus
-
- Moromizato Hidehiko
- Department of Obstetrics & Gynecology, School of Medicine, Faculty of Medicine, University of the Ryukyus
-
- Sakanashi Matao
- Department of Pharmacology, Faculty of Medicine, University of the Ryukyus
Abstract
To estimate the participation of a Na+, K+-ATPase-inhibiting plasma foctor in pregnancy induced hypertension (PIH), the inhibitory activity and the characteristics of plasma extract eluted with ethanol through a C8 column were examined in normotensive non-pregnant women (N) and women with normal pregnancy (NP) and PIH. There were no differences among the 3 groups in the Na+, K+-ATPase activity of erythrocyte ghosts. The heat- and acid-stable plasma extract dose-dependently inhibited Na+, K+-ATPase activity with a pattern similar to that of ouabain, but different from that of vanadate. The inhibitory activity of plasma extract was not influenced by polyclonal digoxin antibody which almost completely prevented digoxin-induced inhibition and slightly but significantly reduced the ouabain-induced one. The results indicate that the plasma extract has ouabain-like inhibitory activity on Na+, K+-ATPase and that it is not endogenously synthesized digoxin itself, but a substance differing in structure from digoxin. Furthermore, the ouabain-like Na+, K+-ATPase inhibitory activity in NP plasma was significantly lower than that in PIH plasma, which was similar to that in N plasma. There were significant relationships between the ouabain-like Na+, K+-ATPase inhibitory activities in plasma and the diastolic and systolic blood pressures in NP and PIH groups. The results suggest that the lower ouabain-like Na+, K+-ATPase inhibitory activity in plasma probably participates in maintaining the blood pressure within the normal range during pregnancy and its failure may be involved in the genesis of PIH.
Journal
-
- The Japanese Journal of Pharmacology
-
The Japanese Journal of Pharmacology 57 (4), 571-581, 1991
The Japanese Pharmacological Society
