Digibind reverses inhibition of cellular rb+ uptake caused by endogenous sodium pump inhibitors present in serum and placenta of women with preeclampsia.
BACKGROUND
Mechanisms mediating preeclampsia (PE) are unclear. Endogenous digitalis-like factors (EDLFs) are sodium pump (SP) inhibitors implicated in essential hypertension, but not fully explored in PE. This study asks whether EDLFs are present and increased in PE and considers their source.


METHODS
EDLF in sera and placentas from third trimester women with uncomplicated pregnancies or PE was assessed by a Rb(+) uptake assay. A digoxin antibody Fab fragment (Digibind) known to inactivate EDLFs was also used to assess EDLFs.


RESULTS
PE serum caused significantly more SP inhibition than serum from uncomplicated pregnancies. This inhibition was concentration-dependent and reversed by Digibind. Serum from uncomplicated pregnancies showed no concentration-dependence or reversal with Digibind. Placental homogenates from control women showed little SP inhibition, but homogenates from PE women showed marked SP inhibition reversed by Digibind.


CONCLUSIONS
These studies evidence EDLF in PE serum. Additionally, PE placentas have high EDLF and may represent a source.
Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
Moana L
ML
Hopoate-Sitake
C David
CD
Adair
Lorrie A
LA
Mason
Carlos
C
Torres
Joseph
J
Kipikasa
Steven W
SW
Graves
D001798:Blood Proteins / Q000378:metabolism; D002298:Cardenolides / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000188:drug therapy / Q000378:metabolism; D007140:Immunoglobulin Fab Fragments / Q000494:pharmacology*; D066298:In Vitro Techniques; D009215:Myometrium / Q000187:drug effects / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000188:drug therapy / Q000378:metabolism*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third / Q000378:metabolism; D012413:Rubidium / Q000493:pharmacokinetics; D012503:Saponins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D001798:Blood Proteins; D002298:Cardenolides; D007140:Immunoglobulin Fab Fragments; D012503:Saponins; C050199:digoxin antibodies Fab fragments; C034504:digoxin-like factors; D000254:Sodium-Potassium-Exchanging ATPase; D012413:Rubidium