Item – Theses Canada

OCLC number
46562323
Author
Lu, Bing,1966-
Title
The effect of oxidative stress on vanadate and insulin stimulation of glucose uptake in rat adipocytes.
Degree
M. Sc. -- University of Toronto, 1996
Publisher
Ottawa :National Library of Canada = Bibliothèque nationale du Canada,1997.
Description
2 microfiches.
Notes
Includes bibliographical references.
Abstract
Rat adipocytes rendered insulin resistant by high glucose and high insulin showed a paradoxical increase in sensitivity to vanadate, an insulin-mimetic agent which inhibits protein tyrosine phosphatases (PTPs). Vanadate (+5) is reduced to the inactive vanadyl (+4) intracellularly by glutathione (GSH). Depletion of GSH by BSO (buthionine sulfoximine) resulted in an enhanced sensitivity to vanadate, decreased levels of GSH and vanadyl while NAC (N-acetylcysteine) pretreatment prior to high glucose/insulin prevented these changes. BSO also mimicked insulin resistance caused by high glucose/insulin in adipocytes from heavier (275-325g) rats, which was partially prevented by NAC pretreatment. In conclusion: Vanadate sensitivity of cells is determined at least in part by intracellular GSH content and the capacity of cells to reduce vanadate to vanadyl. Furthermore, the pathogenesis of insulin resistance appears to be related at least in part, particularly insulin sensitivity, to oxidative stress.
ISBN
0612192296
9780612192294