An exaggerated oxidative stress has been postulated as the link
between diabetes mellitus (D.M) and endothelial dysfunction.
This study aimed to investigate the possible therapeutic effect
of chronic zinc administration (0.5% in drinking water) on renal artery vascular reactivity and oxidative stress indices viz
serum oxidized to reduced glutathione ratio (GSH/GSSG).
trolox equivalent antioxidant capacity (TEAC) and lipohydroperoxides.(LPO) in experimentally-induced D.M by streptozotocin (STZ) (60 mg/kg i.p single dose) in rats. Using Doppler technique in this study indicated that chronic zinc
administration significantly (p<0.05) improved renal artery
vascular reactivity to acetylcholine (Ach). Such an effect
which seemed to be mediated by two mechanisms: (1) Zinc restored plasma antioxidant defenses as it significantly (p<0.05)
Increased the GSH/GSSG ratio. the (TEAC) and significantly
(pc0.05) decreased LPO. This resulted in lowering the
quenching effect of free radicals on nitric oxide (NO). (2)
Chronic zinc administration significantly (pc0.05) increased
intracellular Mg 2+ concentration and significantly (p<0.05) decreased intracellular Ca 2+ content, thus protecting against oxidative cell damage and improving smooth vascular cell relaxation respectively |
