Uptake of zinc by human placental microvillus border membranes and characterization of the effects of cadmium on this process.
The uptake of Zinc (Zn) by microvillus border membrane vesicles formed from the trophoblast of term human placentae is markedly increased over brief periods of incubation with much slower increases persisting for up to 2 h of incubation. Zinc is both bound to membrane components and transported into intravesicular osmotically active space. Uptake is saturable, temperature dependent from 4 to 37 degrees C with a Q10 of 1.7, and is inhibited by the sulphydryl agent DTNB. About 20 per cent of the uptake is susceptible to inhibition by Cadmium (Cd) at concentrations from 5 to 50 microM, a significant part of the action of this metal being on the transmembrane component of Zn uptake.
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K R
KR
Physiology Division, School of Biomedical Sciences, University of Aberdeen, UK.
Abramovich
D R
DR
Aggett
P J
PJ
Bain
M
M
Chipperfield
A R
AR
Durdy
H
H
McLachlan
J
J
Smale
A
A
D002104:Cadmium / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008871:Microvilli / Q000378:metabolism; D010920:Placenta / Q000378:metabolism* / Q000648:ultrastructure; D011247:Pregnancy; D015032:Zinc / Q000378:metabolism*
D002104:Cadmium; D015032:Zinc