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Multiple sites of vanadate and peroxovanadate action in Xenopus oocytes
Author(s) -
Barnes David M.,
Sykes Destiny B.,
Shechter Yoram,
Miller David S.
Publication year - 1995
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1041620119
Subject(s) - vanadate , microinjection , hexose , biochemistry , xenopus , stimulation , intracellular , chemistry , extracellular , biology , microbiology and biotechnology , endocrinology , gene , enzyme
In Xenopus laevis oocytes, the insulin mimics, vanadate and peroxovandates (PV), stimulated the uptake of 3 H‐2‐deoxyglucose and incorporation of 35 S‐methionine into protein. For both hexose transport and protein synthesis, peroxovandates (produced by reacting vandate and H 2 O 2 ) were at least as potent as vandate. Microinjection of peroxovandates into the oocytes stimulated 2‐deoxyglucose uptake. However, methionine incorporation was not stimulated by microinjection of peroxovanadate or vanadate solutions. Consistent with these results and with the possibility that vandate and peroxovandates enter the cell on a phosphate transporter, raising the medium phosphate concentration from 1 mM to 10 mM blocked vanadate‐stimulated hexose transport and partially reduced peroxovanadates stimulation of hexose transport. Increased medium phosphate did not reduce stimulation of protein synthesis by either effector. Taken together, these data indicate that vanadate/peroxovanadates act at both intracellular and extracellular sites. Action at the former stimulates hexose uptake and action at the latter, protein synthesis. © 1995 Wiley‐Liss, Inc. This artilce is a US Government work and, as such, is in the public domain in the United States of America.